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Kernel panic #20
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Edit: never mind, I didn't read the trace. There is this in the log above the panic:
and it comes while running the initialization for the example module (
and then it crashes while copying some memory. Let me try to reproduce it. |
Here is my initrd, if you want to use it. |
Reproduced with LLVM 10 on my side. |
Mine was llvm11, as packages in my nix flake |
Some kernel configs were panicking at the Rust example driver initialization. The `__MOD` static value had a bogus value, which meant that trying to initialize it was dropping the object that was, supposedly, there. The memory corruption happened during rootfs unpacking, which explains why it only happened in some configs (like in CI) and why it also didn't happen if there was an early error during unpacking. That memory corruption, in turn, was caused because the `__MOD` symbol was being placed after the end of the kernel reserve. That happened due to the kernel's linker script not supporting unique sections per symbol for dead code data elimination -- yet. Some arches do, but until we can rely on that, we need to disable their generation in rustc's side for the moment. Since we discussed to have the target spec on our side, and since `-Z function-sections=false` was added just a month ago, I went with the spec route. Other symbols were being placed in unexpected places, which should be fixed now too. Signed-off-by: Miguel Ojeda <[email protected]>
Forbid rustc from using -f{function,data}-sections (fixes #20 panic)
The test_generic_metric() missed to release entries in the pctx. Asan reported following leak (and more): Direct leak of 128 byte(s) in 1 object(s) allocated from: #0 0x7f4c9396980e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e) #1 0x55f7e748cc14 in hashmap_grow (/home/namhyung/project/linux/tools/perf/perf+0x90cc14) #2 0x55f7e748d497 in hashmap__insert (/home/namhyung/project/linux/tools/perf/perf+0x90d497) #3 0x55f7e7341667 in hashmap__set /home/namhyung/project/linux/tools/perf/util/hashmap.h:111 #4 0x55f7e7341667 in expr__add_ref util/expr.c:120 #5 0x55f7e7292436 in prepare_metric util/stat-shadow.c:783 #6 0x55f7e729556d in test_generic_metric util/stat-shadow.c:858 #7 0x55f7e712390b in compute_single tests/parse-metric.c:128 #8 0x55f7e712390b in __compute_metric tests/parse-metric.c:180 #9 0x55f7e712446d in compute_metric tests/parse-metric.c:196 #10 0x55f7e712446d in test_dcache_l2 tests/parse-metric.c:295 #11 0x55f7e712446d in test__parse_metric tests/parse-metric.c:355 #12 0x55f7e70be09b in run_test tests/builtin-test.c:410 #13 0x55f7e70be09b in test_and_print tests/builtin-test.c:440 #14 0x55f7e70c101a in __cmd_test tests/builtin-test.c:661 #15 0x55f7e70c101a in cmd_test tests/builtin-test.c:807 #16 0x55f7e7126214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #17 0x55f7e6fc41a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #18 0x55f7e6fc41a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #19 0x55f7e6fc41a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #20 0x7f4c93492cc9 in __libc_start_main ../csu/libc-start.c:308 Fixes: 6d432c4 ("perf tools: Add test_generic_metric function") Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
The evlist and the cpu/thread maps should be released together. Otherwise following error was reported by Asan. Note that this test still has memory leaks in DSOs so it still fails even after this change. I'll take a look at that too. # perf test -v 26 26: Object code reading : --- start --- test child forked, pid 154184 Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. symsrc__init: cannot get elf header. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols Parsing event 'cycles' mmap size 528384B ... ================================================================= ==154184==ERROR: LeakSanitizer: detected memory leaks Direct leak of 439 byte(s) in 1 object(s) allocated from: #0 0x7fcb66e77037 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:154 #1 0x55ad9b7e821e in dso__new_id util/dso.c:1256 #2 0x55ad9b8cfd4a in __machine__addnew_vdso util/vdso.c:132 #3 0x55ad9b8cfd4a in machine__findnew_vdso util/vdso.c:347 #4 0x55ad9b845b7e in map__new util/map.c:176 #5 0x55ad9b8415a2 in machine__process_mmap2_event util/machine.c:1787 #6 0x55ad9b8fab16 in perf_tool__process_synth_event util/synthetic-events.c:64 #7 0x55ad9b8fab16 in perf_event__synthesize_mmap_events util/synthetic-events.c:499 #8 0x55ad9b8fbfdf in __event__synthesize_thread util/synthetic-events.c:741 #9 0x55ad9b8ff3e3 in perf_event__synthesize_thread_map util/synthetic-events.c:833 #10 0x55ad9b738585 in do_test_code_reading tests/code-reading.c:608 #11 0x55ad9b73b25d in test__code_reading tests/code-reading.c:722 #12 0x55ad9b6f28fb in run_test tests/builtin-test.c:428 #13 0x55ad9b6f28fb in test_and_print tests/builtin-test.c:458 #14 0x55ad9b6f4a53 in __cmd_test tests/builtin-test.c:679 #15 0x55ad9b6f4a53 in cmd_test tests/builtin-test.c:825 #16 0x55ad9b760cc4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313 #17 0x55ad9b5eaa88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365 #18 0x55ad9b5eaa88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409 #19 0x55ad9b5eaa88 in main /home/namhyung/project/linux/tools/perf/perf.c:539 #20 0x7fcb669acd09 in __libc_start_main ../csu/libc-start.c:308 ... SUMMARY: AddressSanitizer: 471 byte(s) leaked in 2 allocation(s). test child finished with 1 ---- end ---- Object code reading: FAILED! Signed-off-by: Namhyung Kim <[email protected]> Acked-by: Jiri Olsa <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
When the kernel is built with CONFIG_KASAN_HW_TAGS and the CPU supports MTE, memory accesses are checked at 16-byte granularity, and out-of-bounds accesses can result in tag check faults. Our current implementation of strlen() makes unaligned 16-byte accesses (within a naturally aligned 4096-byte window), and can trigger tag check faults. This can be seen at boot time, e.g. | BUG: KASAN: invalid-access in __pi_strlen+0x14/0x150 | Read at addr f4ff0000c0028300 by task swapper/0/0 | Pointer tag: [f4], memory tag: [fe] | | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.13.0-09550-g03c2813535a2-dirty #20 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0x0/0x1b0 | show_stack+0x1c/0x30 | dump_stack_lvl+0x68/0x84 | print_address_description+0x7c/0x2b4 | kasan_report+0x138/0x38c | __do_kernel_fault+0x190/0x1c4 | do_tag_check_fault+0x78/0x90 | do_mem_abort+0x44/0xb4 | el1_abort+0x40/0x60 | el1h_64_sync_handler+0xb0/0xd0 | el1h_64_sync+0x78/0x7c | __pi_strlen+0x14/0x150 | __register_sysctl_table+0x7c4/0x890 | register_leaf_sysctl_tables+0x1a4/0x210 | register_leaf_sysctl_tables+0xc8/0x210 | __register_sysctl_paths+0x22c/0x290 | register_sysctl_table+0x2c/0x40 | sysctl_init+0x20/0x30 | proc_sys_init+0x3c/0x48 | proc_root_init+0x80/0x9c | start_kernel+0x640/0x69c | __primary_switched+0xc0/0xc8 To fix this, we can reduce the (strlen-internal) MIN_PAGE_SIZE to 16 bytes when CONFIG_KASAN_HW_TAGS is selected. This will cause strlen() to align the base pointer downwards to a 16-byte boundary, and to discard the additional prefix bytes without counting them. All subsequent accesses will be 16-byte aligned 16-byte LDPs. While the comments say the body of the loop will access 32 bytes, this is performed as two 16-byte acceses, with the second made only if the first did not encounter a NUL byte, so the body of the loop will not over-read across a 16-byte boundary. No other string routines are affected. The other str*() routines will not make any access which straddles a 16-byte boundary, and the mem*() routines will only make acceses which straddle a 16-byte boundary when which is entirely within the bounds of the relevant base and size arguments. Fixes: 325a1de ("arm64: Import updated version of Cortex Strings' strlen") Signed-off-by: Mark Rutland <[email protected]> Cc: Alexander Potapenko <[email protected] Cc: Andrey Konovalov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Cc: Robin Murphy <[email protected]> Cc: Will Deacon <[email protected]> Reviewed-by: Catalin Marinas <[email protected]> Reviewed-by: Robin Murphy <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Will Deacon <[email protected]>
arm32 uses software to simulate the instruction replaced by kprobe. some instructions may be simulated by constructing assembly functions. therefore, before executing instruction simulation, it is necessary to construct assembly function execution environment in C language through binding registers. after kasan is enabled, the register binding relationship will be destroyed, resulting in instruction simulation errors and causing kernel panic. the kprobe emulate instruction function is distributed in three files: actions-common.c actions-arm.c actions-thumb.c, so disable KASAN when compiling these files. for example, use kprobe insert on cap_capable+20 after kasan enabled, the cap_capable assembly code is as follows: <cap_capable>: e92d47f0 push {r4, r5, r6, r7, r8, r9, sl, lr} e1a05000 mov r5, r0 e280006c add r0, r0, #108 ; 0x6c e1a04001 mov r4, r1 e1a06002 mov r6, r2 e59fa090 ldr sl, [pc, #144] ; ebfc7bf8 bl c03aa4b4 <__asan_load4> e595706c ldr r7, [r5, #108] ; 0x6c e2859014 add r9, r5, #20 ...... The emulate_ldr assembly code after enabling kasan is as follows: c06f1384 <emulate_ldr>: e92d47f0 push {r4, r5, r6, r7, r8, r9, sl, lr} e282803c add r8, r2, #60 ; 0x3c e1a05000 mov r5, r0 e7e37855 ubfx r7, r5, #16, #4 e1a00008 mov r0, r8 e1a09001 mov r9, r1 e1a04002 mov r4, r2 ebf35462 bl c03c6530 <__asan_load4> e357000f cmp r7, #15 e7e36655 ubfx r6, r5, #12, #4 e205a00f and sl, r5, #15 0a000001 beq c06f13bc <emulate_ldr+0x38> e0840107 add r0, r4, r7, lsl #2 ebf3545c bl c03c6530 <__asan_load4> e084010a add r0, r4, sl, lsl #2 ebf3545a bl c03c6530 <__asan_load4> e2890010 add r0, r9, #16 ebf35458 bl c03c6530 <__asan_load4> e5990010 ldr r0, [r9, #16] e12fff30 blx r0 e356000f cm r6, #15 1a000014 bne c06f1430 <emulate_ldr+0xac> e1a06000 mov r6, r0 e2840040 add r0, r4, #64 ; 0x40 ...... when running in emulate_ldr to simulate the ldr instruction, panic occurred, and the log is as follows: Unable to handle kernel NULL pointer dereference at virtual address 00000090 pgd = ecb46400 [00000090] *pgd=2e0fa003, *pmd=00000000 Internal error: Oops: 206 [#1] SMP ARM PC is at cap_capable+0x14/0xb0 LR is at emulate_ldr+0x50/0xc0 psr: 600d0293 sp : ecd63af8 ip : 00000004 fp : c0a7c30c r10: 00000000 r9 : c30897f4 r8 : ecd63cd4 r7 : 0000000f r6 : 0000000a r5 : e59fa090 r4 : ecd63c98 r3 : c06ae294 r2 : 00000000 r1 : b7611300 r0 : bf4ec008 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user Control: 32c5387d Table: 2d546400 DAC: 55555555 Process bash (pid: 1643, stack limit = 0xecd60190) (cap_capable) from (kprobe_handler+0x218/0x340) (kprobe_handler) from (kprobe_trap_handler+0x24/0x48) (kprobe_trap_handler) from (do_undefinstr+0x13c/0x364) (do_undefinstr) from (__und_svc_finish+0x0/0x30) (__und_svc_finish) from (cap_capable+0x18/0xb0) (cap_capable) from (cap_vm_enough_memory+0x38/0x48) (cap_vm_enough_memory) from (security_vm_enough_memory_mm+0x48/0x6c) (security_vm_enough_memory_mm) from (copy_process.constprop.5+0x16b4/0x25c8) (copy_process.constprop.5) from (_do_fork+0xe8/0x55c) (_do_fork) from (SyS_clone+0x1c/0x24) (SyS_clone) from (__sys_trace_return+0x0/0x10) Code: 0050a0e1 6c0080e2 0140a0e1 0260a0e1 (f801f0e7) Fixes: 35aa1df ("ARM kprobes: instruction single-stepping support") Fixes: 4210157 ("ARM: 9017/2: Enable KASan for ARM") Signed-off-by: huangshaobo <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Signed-off-by: Russell King (Oracle) <[email protected]>
When bringing down the netdevice or system shutdown, a panic can be triggered while accessing the sysfs path because the device is already removed. [ 755.549084] mlx5_core 0000:12:00.1: Shutdown was called [ 756.404455] mlx5_core 0000:12:00.0: Shutdown was called ... [ 757.937260] BUG: unable to handle kernel NULL pointer dereference at (null) [ 758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280 crash> bt ... PID: 12649 TASK: ffff8924108f2100 CPU: 1 COMMAND: "amsd" ... #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778 [exception RIP: dma_pool_alloc+0x1ab] RIP: ffffffff8ee11acb RSP: ffff89240e1a3968 RFLAGS: 00010046 RAX: 0000000000000246 RBX: ffff89243d874100 RCX: 0000000000001000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff89243d874090 RBP: ffff89240e1a39c0 R8: 000000000001f080 R9: ffff8905ffc03c00 R10: ffffffffc04680d4 R11: ffffffff8edde9fd R12: 00000000000080d0 R13: ffff89243d874090 R14: ffff89243d874080 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core] #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core] #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core] #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core] #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core] #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core] #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core] #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46 #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208 #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3 #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596 #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10 #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5 #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92 crash> net_device.state ffff89443b0c0000 state = 0x5 (__LINK_STATE_START| __LINK_STATE_NOCARRIER) To prevent this scenario, we also make sure that the netdevice is present. Signed-off-by: suresh kumar <[email protected]> Signed-off-by: David S. Miller <[email protected]>
The following WARN is triggered from kvm_vm_ioctl_set_clock(): WARNING: CPU: 10 PID: 579353 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:3161 mark_page_dirty_in_slot+0x6c/0x80 [kvm] ... CPU: 10 PID: 579353 Comm: qemu-system-x86 Tainted: G W O 5.16.0.stable #20 Hardware name: LENOVO 20UF001CUS/20UF001CUS, BIOS R1CET65W(1.34 ) 06/17/2021 RIP: 0010:mark_page_dirty_in_slot+0x6c/0x80 [kvm] ... Call Trace: <TASK> ? kvm_write_guest+0x114/0x120 [kvm] kvm_hv_invalidate_tsc_page+0x9e/0xf0 [kvm] kvm_arch_vm_ioctl+0xa26/0xc50 [kvm] ? schedule+0x4e/0xc0 ? __cond_resched+0x1a/0x50 ? futex_wait+0x166/0x250 ? __send_signal+0x1f1/0x3d0 kvm_vm_ioctl+0x747/0xda0 [kvm] ... The WARN was introduced by commit 03c0304 ("KVM: Warn if mark_page_dirty() is called without an active vCPU") but the change seems to be correct (unlike Hyper-V TSC page update mechanism). In fact, there's no real need to actually write to guest memory to invalidate TSC page, this can be done by the first vCPU which goes through kvm_guest_time_update(). Reported-by: Maxim Levitsky <[email protected]> Reported-by: Naresh Kamboju <[email protected]> Suggested-by: Sean Christopherson <[email protected]> Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]>
When a system with E810 with existing VFs gets rebooted the following hang may be observed. Pid 1 is hung in iavf_remove(), part of a network driver: PID: 1 TASK: ffff965400e5a340 CPU: 24 COMMAND: "systemd-shutdow" #0 [ffffaad04005fa50] __schedule at ffffffff8b3239cb #1 [ffffaad04005fae8] schedule at ffffffff8b323e2d #2 [ffffaad04005fb00] schedule_hrtimeout_range_clock at ffffffff8b32cebc #3 [ffffaad04005fb80] usleep_range_state at ffffffff8b32c930 #4 [ffffaad04005fbb0] iavf_remove at ffffffffc12b9b4c [iavf] #5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513 #6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa #7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc #8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e #9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429 #10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4 #11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice] #12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice] #13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice] #14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1 #15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386 #16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870 #17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6 #18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159 #19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc #20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d #21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169 #22 [ffffaad04005ff50] entry_SYSCALL_64_after_hwframe at ffffffff8b40009b RIP: 00007f1baa5c13d7 RSP: 00007fffbcc55a98 RFLAGS: 00000202 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1baa5c13d7 RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead RBP: 00007fffbcc55ca0 R8: 0000000000000000 R9: 00007fffbcc54e90 R10: 00007fffbcc55050 R11: 0000000000000202 R12: 0000000000000005 R13: 0000000000000000 R14: 00007fffbcc55af0 R15: 0000000000000000 ORIG_RAX: 00000000000000a9 CS: 0033 SS: 002b During reboot all drivers PM shutdown callbacks are invoked. In iavf_shutdown() the adapter state is changed to __IAVF_REMOVE. In ice_shutdown() the call chain above is executed, which at some point calls iavf_remove(). However iavf_remove() expects the VF to be in one of the states __IAVF_RUNNING, __IAVF_DOWN or __IAVF_INIT_FAILED. If that's not the case it sleeps forever. So if iavf_shutdown() gets invoked before iavf_remove() the system will hang indefinitely because the adapter is already in state __IAVF_REMOVE. Fix this by returning from iavf_remove() if the state is __IAVF_REMOVE, as we already went through iavf_shutdown(). Fixes: 9745780 ("iavf: Add waiting so the port is initialized in remove") Fixes: a841733 ("iavf: Fix race condition between iavf_shutdown and iavf_remove") Reported-by: Marius Cornea <[email protected]> Signed-off-by: Stefan Assmann <[email protected]> Reviewed-by: Michal Kubiak <[email protected]> Tested-by: Rafal Romanowski <[email protected]> Signed-off-by: Tony Nguyen <[email protected]>
…_write() If a user can make copy_from_user() fail, there is a potential for UAF/DF due to a lack of locking around the allocation, use and freeing of the data buffers. This issue is not theoretical. I managed to author a POC for it: BUG: KASAN: double-free in kfree+0x5c/0xac Free of addr ffff29280be5de00 by task poc/356 CPU: 1 PID: 356 Comm: poc Not tainted 6.1.0-00001-g961aa6552c04-dirty #20 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 show_stack+0x18/0x40 dump_stack_lvl+0x64/0x80 print_report+0x188/0x48c kasan_report_invalid_free+0xa0/0xc0 ____kasan_slab_free+0x174/0x1b0 __kasan_slab_free+0x18/0x24 __kmem_cache_free+0x130/0x2e0 kfree+0x5c/0xac mbox_test_message_write+0x208/0x29c full_proxy_write+0x90/0xf0 vfs_write+0x154/0x440 ksys_write+0xcc/0x180 __arm64_sys_write+0x44/0x60 invoke_syscall+0x60/0x190 el0_svc_common.constprop.0+0x7c/0x160 do_el0_svc+0x40/0xf0 el0_svc+0x2c/0x6c el0t_64_sync_handler+0xf4/0x120 el0t_64_sync+0x18c/0x190 Allocated by task 356: kasan_save_stack+0x3c/0x70 kasan_set_track+0x2c/0x40 kasan_save_alloc_info+0x24/0x34 __kasan_kmalloc+0xb8/0xc0 kmalloc_trace+0x58/0x70 mbox_test_message_write+0x6c/0x29c full_proxy_write+0x90/0xf0 vfs_write+0x154/0x440 ksys_write+0xcc/0x180 __arm64_sys_write+0x44/0x60 invoke_syscall+0x60/0x190 el0_svc_common.constprop.0+0x7c/0x160 do_el0_svc+0x40/0xf0 el0_svc+0x2c/0x6c el0t_64_sync_handler+0xf4/0x120 el0t_64_sync+0x18c/0x190 Freed by task 357: kasan_save_stack+0x3c/0x70 kasan_set_track+0x2c/0x40 kasan_save_free_info+0x38/0x5c ____kasan_slab_free+0x13c/0x1b0 __kasan_slab_free+0x18/0x24 __kmem_cache_free+0x130/0x2e0 kfree+0x5c/0xac mbox_test_message_write+0x208/0x29c full_proxy_write+0x90/0xf0 vfs_write+0x154/0x440 ksys_write+0xcc/0x180 __arm64_sys_write+0x44/0x60 invoke_syscall+0x60/0x190 el0_svc_common.constprop.0+0x7c/0x160 do_el0_svc+0x40/0xf0 el0_svc+0x2c/0x6c el0t_64_sync_handler+0xf4/0x120 el0t_64_sync+0x18c/0x190 Signed-off-by: Lee Jones <[email protected]> Signed-off-by: Jassi Brar <[email protected]>
The following processes run into a deadlock. CPU 41 was waiting for CPU 29 to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29 was hung by that spinlock with IRQs disabled. PID: 17360 TASK: ffff95c1090c5c40 CPU: 41 COMMAND: "mrdiagd" !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0 !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0 !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0 # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0 # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0 # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0 # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0 # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0 # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0 # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0 #10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0 #11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0 #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0 #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0 #14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0 #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0 #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0 #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0 #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0 #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0 #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0 #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0 #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0 #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0 #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0 #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0 #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0 #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0 PID: 17355 TASK: ffff95c1090c3d80 CPU: 29 COMMAND: "mrdiagd" !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0 !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0 # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0 # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0 # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0 # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0 # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0 # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0 # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0 # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0 #10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0 #11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0 #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0 #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0 #14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0 #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0 #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0 #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0 The lock is used to synchronize different sysfs operations, it doesn't protect any resource that will be touched by an interrupt. Consequently it's not required to disable IRQs. Replace the spinlock with a mutex to fix the deadlock. Signed-off-by: Junxiao Bi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Mike Christie <[email protected]> Cc: [email protected] Signed-off-by: Martin K. Petersen <[email protected]>
Inject fault while probing mdpy.ko, if kstrdup() of create_dir() fails in kobject_add_internal() in kobject_init_and_add() in mdev_type_add() in parent_create_sysfs_files(), it will return 0 and probe successfully. And when rmmod mdpy.ko, the mdpy_dev_exit() will call mdev_unregister_parent(), the mdev_type_remove() may traverse uninitialized parent->types[i] in parent_remove_sysfs_files(), and it will cause below null-ptr-deref. If mdev_type_add() fails, return the error code and kset_unregister() to fix the issue. general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 2 PID: 10215 Comm: rmmod Tainted: G W N 6.6.0-rc2+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:__kobject_del+0x62/0x1c0 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8 RSP: 0018:ffff88810695fd30 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1 R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000 R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660 FS: 00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0 DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: <TASK> ? die_addr+0x3d/0xa0 ? exc_general_protection+0x144/0x220 ? asm_exc_general_protection+0x22/0x30 ? __kobject_del+0x62/0x1c0 kobject_del+0x32/0x50 parent_remove_sysfs_files+0xd6/0x170 [mdev] mdev_unregister_parent+0xfb/0x190 [mdev] ? mdev_register_parent+0x270/0x270 [mdev] ? find_module_all+0x9d/0xe0 mdpy_dev_exit+0x17/0x63 [mdpy] __do_sys_delete_module.constprop.0+0x2fa/0x4b0 ? module_flags+0x300/0x300 ? __fput+0x4e7/0xa00 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fbc813221b7 Code: 73 01 c3 48 8b 0d d1 8c 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 8c 2c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe780e0648 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 00007ffe780e06a8 RCX: 00007fbc813221b7 RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055e214df9b58 RBP: 000055e214df9af0 R08: 00007ffe780df5c1 R09: 0000000000000000 R10: 00007fbc8139ecc0 R11: 0000000000000206 R12: 00007ffe780e0870 R13: 00007ffe780e0ed0 R14: 000055e214df9260 R15: 000055e214df9af0 </TASK> Modules linked in: mdpy(-) mdev vfio_iommu_type1 vfio [last unloaded: mdpy] Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 0000000000000000 ]--- RIP: 0010:__kobject_del+0x62/0x1c0 Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 51 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 28 48 8d 7d 10 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 24 01 00 00 48 8b 75 10 48 89 df 48 8d 6b 3c e8 RSP: 0018:ffff88810695fd30 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffffa0270268 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000004 RDI: 0000000000000010 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10233a4ef1 R10: ffff888119d2778b R11: 0000000063666572 R12: 0000000000000000 R13: fffffbfff404e2d4 R14: dffffc0000000000 R15: ffffffffa0271660 FS: 00007fbc81981540(0000) GS:ffff888119d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc14a142dc0 CR3: 0000000110a62003 CR4: 0000000000770ee0 DR0: ffffffff8fb0bce8 DR1: ffffffff8fb0bce9 DR2: ffffffff8fb0bcea DR3: ffffffff8fb0bceb DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 1 seconds.. Fixes: da44c34 ("vfio/mdev: simplify mdev_type handling") Signed-off-by: Jinjie Ruan <[email protected]> Reviewed-by: Eric Farman <[email protected]> Reviewed-by: Jason Gunthorpe <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alex Williamson <[email protected]>
When creating ceq_0 during probing irdma, cqp.sc_cqp will be sent as a cqp_request to cqp->sc_cqp.sq_ring. If the request is pending when removing the irdma driver or unplugging its aux device, cqp.sc_cqp will be dereferenced as wrong struct in irdma_free_pending_cqp_request(). PID: 3669 TASK: ffff88aef892c000 CPU: 28 COMMAND: "kworker/28:0" #0 [fffffe0000549e38] crash_nmi_callback at ffffffff810e3a34 #1 [fffffe0000549e40] nmi_handle at ffffffff810788b2 #2 [fffffe0000549ea0] default_do_nmi at ffffffff8107938f #3 [fffffe0000549eb8] do_nmi at ffffffff81079582 #4 [fffffe0000549ef0] end_repeat_nmi at ffffffff82e016b4 [exception RIP: native_queued_spin_lock_slowpath+1291] RIP: ffffffff8127e72b RSP: ffff88aa841ef778 RFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88b01f849700 RCX: ffffffff8127e47e RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff83857ec0 RBP: ffff88afe3e4efc8 R8: ffffed15fc7c9dfa R9: ffffed15fc7c9dfa R10: 0000000000000001 R11: ffffed15fc7c9df9 R12: 0000000000740000 R13: ffff88b01f849708 R14: 0000000000000003 R15: ffffed1603f092e1 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 -- <NMI exception stack> -- #5 [ffff88aa841ef778] native_queued_spin_lock_slowpath at ffffffff8127e72b #6 [ffff88aa841ef7b0] _raw_spin_lock_irqsave at ffffffff82c22aa4 #7 [ffff88aa841ef7c8] __wake_up_common_lock at ffffffff81257363 #8 [ffff88aa841ef888] irdma_free_pending_cqp_request at ffffffffa0ba12cc [irdma] #9 [ffff88aa841ef958] irdma_cleanup_pending_cqp_op at ffffffffa0ba1469 [irdma] #10 [ffff88aa841ef9c0] irdma_ctrl_deinit_hw at ffffffffa0b2989f [irdma] #11 [ffff88aa841efa28] irdma_remove at ffffffffa0b252df [irdma] #12 [ffff88aa841efae8] auxiliary_bus_remove at ffffffff8219afdb #13 [ffff88aa841efb00] device_release_driver_internal at ffffffff821882e6 #14 [ffff88aa841efb38] bus_remove_device at ffffffff82184278 #15 [ffff88aa841efb88] device_del at ffffffff82179d23 #16 [ffff88aa841efc48] ice_unplug_aux_dev at ffffffffa0eb1c14 [ice] #17 [ffff88aa841efc68] ice_service_task at ffffffffa0d88201 [ice] #18 [ffff88aa841efde8] process_one_work at ffffffff811c589a #19 [ffff88aa841efe60] worker_thread at ffffffff811c71ff #20 [ffff88aa841eff10] kthread at ffffffff811d87a0 #21 [ffff88aa841eff50] ret_from_fork at ffffffff82e0022f Fixes: 44d9e52 ("RDMA/irdma: Implement device initialization definitions") Link: https://lore.kernel.org/r/[email protected] Suggested-by: "Ismail, Mustafa" <[email protected]> Signed-off-by: Shifeng Li <[email protected]> Reviewed-by: Shiraz Saleem <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]>
When running autonuma with enabling multi-size THP, I encountered the following kernel crash issue: [ 134.290216] list_del corruption. prev->next should be fffff9ad42e1c490, but was dead000000000100. (prev=fffff9ad42399890) [ 134.290877] kernel BUG at lib/list_debug.c:62! [ 134.291052] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 134.291210] CPU: 56 PID: 8037 Comm: numa01 Kdump: loaded Tainted: G E 6.7.0-rc4+ #20 [ 134.291649] RIP: 0010:__list_del_entry_valid_or_report+0x97/0xb0 ...... [ 134.294252] Call Trace: [ 134.294362] <TASK> [ 134.294440] ? die+0x33/0x90 [ 134.294561] ? do_trap+0xe0/0x110 ...... [ 134.295681] ? __list_del_entry_valid_or_report+0x97/0xb0 [ 134.295842] folio_undo_large_rmappable+0x99/0x100 [ 134.296003] destroy_large_folio+0x68/0x70 [ 134.296172] migrate_folio_move+0x12e/0x260 [ 134.296264] ? __pfx_remove_migration_pte+0x10/0x10 [ 134.296389] migrate_pages_batch+0x495/0x6b0 [ 134.296523] migrate_pages+0x1d0/0x500 [ 134.296646] ? __pfx_alloc_misplaced_dst_folio+0x10/0x10 [ 134.296799] migrate_misplaced_folio+0x12d/0x2b0 [ 134.296953] do_numa_page+0x1f4/0x570 [ 134.297121] __handle_mm_fault+0x2b0/0x6c0 [ 134.297254] handle_mm_fault+0x107/0x270 [ 134.300897] do_user_addr_fault+0x167/0x680 [ 134.304561] exc_page_fault+0x65/0x140 [ 134.307919] asm_exc_page_fault+0x22/0x30 The reason for the crash is that, the commit 85ce2c5 ("memcontrol: only transfer the memcg data for migration") removed the charging and uncharging operations of the migration folios and cleared the memcg data of the old folio. During the subsequent release process of the old large folio in destroy_large_folio(), if the large folio needs to be removed from the split queue, an incorrect split queue can be obtained (which is pgdat->deferred_split_queue) because the old folio's memcg is NULL now. This can lead to list operations being performed under the wrong split queue lock protection, resulting in a list crash as above. After the migration, the old folio is going to be freed, so we can remove it from the split queue in mem_cgroup_migrate() a bit earlier before clearing the memcg data to avoid getting incorrect split queue. [[email protected]: fix comment, per Zi Yan] Link: https://lkml.kernel.org/r/61273e5e9b490682388377c20f52d19de4a80460.1703054559.git.baolin.wang@linux.alibaba.com Fixes: 85ce2c5 ("memcontrol: only transfer the memcg data for migration") Signed-off-by: Baolin Wang <[email protected]> Reviewed-by: Nhat Pham <[email protected]> Reviewed-by: Yang Shi <[email protected]> Reviewed-by: Zi Yan <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: "Huang, Ying" <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Muchun Song <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Shakeel Butt <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
Commit a5a9230 (fbdev: fbcon: Properly revert changes when vc_resize() failed) started restoring old font data upon failure (of vc_resize()). But it performs so only for user fonts. It means that the "system"/internal fonts are not restored at all. So in result, the very first call to fbcon_do_set_font() performs no restore at all upon failing vc_resize(). This can be reproduced by Syzkaller to crash the system on the next invocation of font_get(). It's rather hard to hit the allocation failure in vc_resize() on the first font_set(), but not impossible. Esp. if fault injection is used to aid the execution/failure. It was demonstrated by Sirius: BUG: unable to handle page fault for address: fffffffffffffff8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce Rust-for-Linux#20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286 Call Trace: <TASK> con_font_get drivers/tty/vt/vt.c:4558 [inline] con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752 tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803 vfs_ioctl fs/ioctl.c:51 [inline] ... So restore the font data in any case, not only for user fonts. Note the later 'if' is now protected by 'old_userfont' and not 'old_data' as the latter is always set now. (And it is supposed to be non-NULL. Otherwise we would see the bug above again.) Signed-off-by: Jiri Slaby (SUSE) <[email protected]> Fixes: a5a9230 ("fbdev: fbcon: Properly revert changes when vc_resize() failed") Reported-and-tested-by: Ubisectech Sirius <[email protected]> Cc: Ubisectech Sirius <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Helge Deller <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Daniel Vetter <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fixes: 6ed58ec ("Bluetooth: Use LE buffers for LE traffic") Suggested-by: Luiz Augusto von Dentz <[email protected]> Signed-off-by: Sungwoo Kim <[email protected]> Signed-off-by: Luiz Augusto von Dentz <[email protected]>
The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 #1 __crash_kexec at ffffffff8c1338fa #2 panic at ffffffff8c1d69b9 #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] #10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] #11 dio_complete at ffffffff8c2b9fa7 #12 do_blockdev_direct_IO at ffffffff8c2bc09f #13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] #14 generic_file_direct_write at ffffffff8c1dcf14 #15 __generic_file_write_iter at ffffffff8c1dd07b #16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] #17 aio_write at ffffffff8c2cc72e #18 kmem_cache_alloc at ffffffff8c248dde #19 do_io_submit at ffffffff8c2ccada #20 do_syscall_64 at ffffffff8c004984 #21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <[email protected]> Reviewed-by: Joseph Qi <[email protected]> Reviewed-by: Heming Zhao <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Changwei Ge <[email protected]> Cc: Gang He <[email protected]> Cc: Jun Piao <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
In the TRACE_EVENT(qdisc_reset) NULL dereference occurred from qdisc->dev_queue->dev <NULL> ->name This situation simulated from bunch of veths and Bluetooth disconnection and reconnection. During qdisc initialization, qdisc was being set to noop_queue. In veth_init_queue, the initial tx_num was reduced back to one, causing the qdisc reset to be called with noop, which led to the kernel panic. I've attached the GitHub gist link that C converted syz-execprogram source code and 3 log of reproduced vmcore-dmesg. https://gist.github.com/yskelg/cc64562873ce249cdd0d5a358b77d740 Yeoreum and I use two fuzzing tool simultaneously. One process with syz-executor : https://github.com/google/syzkaller $ ./syz-execprog -executor=./syz-executor -repeat=1 -sandbox=setuid \ -enable=none -collide=false log1 The other process with perf fuzzer: https://github.com/deater/perf_event_tests/tree/master/fuzzer $ perf_event_tests/fuzzer/perf_fuzzer I think this will happen on the kernel version. Linux kernel version +v6.7.10, +v6.8, +v6.9 and it could happen in v6.10. This occurred from 51270d5. I think this patch is absolutely necessary. Previously, It was showing not intended string value of name. I've reproduced 3 time from my fedora 40 Debug Kernel with any other module or patched. version: 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug [ 5287.164555] veth0_vlan: left promiscuous mode [ 5287.164929] veth1_macvtap: left promiscuous mode [ 5287.164950] veth0_macvtap: left promiscuous mode [ 5287.164983] veth1_vlan: left promiscuous mode [ 5287.165008] veth0_vlan: left promiscuous mode [ 5287.165450] veth1_macvtap: left promiscuous mode [ 5287.165472] veth0_macvtap: left promiscuous mode [ 5287.165502] veth1_vlan: left promiscuous mode … [ 5297.598240] bridge0: port 2(bridge_slave_1) entered blocking state [ 5297.598262] bridge0: port 2(bridge_slave_1) entered forwarding state [ 5297.598296] bridge0: port 1(bridge_slave_0) entered blocking state [ 5297.598313] bridge0: port 1(bridge_slave_0) entered forwarding state [ 5297.616090] 8021q: adding VLAN 0 to HW filter on device bond0 [ 5297.620405] bridge0: port 1(bridge_slave_0) entered disabled state [ 5297.620730] bridge0: port 2(bridge_slave_1) entered disabled state [ 5297.627247] 8021q: adding VLAN 0 to HW filter on device team0 [ 5297.629636] bridge0: port 1(bridge_slave_0) entered blocking state … [ 5298.002798] bridge_slave_0: left promiscuous mode [ 5298.002869] bridge0: port 1(bridge_slave_0) entered disabled state [ 5298.309444] bond0 (unregistering): (slave bond_slave_0): Releasing backup interface [ 5298.315206] bond0 (unregistering): (slave bond_slave_1): Releasing backup interface [ 5298.320207] bond0 (unregistering): Released all slaves [ 5298.354296] hsr_slave_0: left promiscuous mode [ 5298.360750] hsr_slave_1: left promiscuous mode [ 5298.374889] veth1_macvtap: left promiscuous mode [ 5298.374931] veth0_macvtap: left promiscuous mode [ 5298.374988] veth1_vlan: left promiscuous mode [ 5298.375024] veth0_vlan: left promiscuous mode [ 5299.109741] team0 (unregistering): Port device team_slave_1 removed [ 5299.185870] team0 (unregistering): Port device team_slave_0 removed … [ 5300.155443] Bluetooth: hci3: unexpected cc 0x0c03 length: 249 > 1 [ 5300.155724] Bluetooth: hci3: unexpected cc 0x1003 length: 249 > 9 [ 5300.155988] Bluetooth: hci3: unexpected cc 0x1001 length: 249 > 9 …. [ 5301.075531] team0: Port device team_slave_1 added [ 5301.085515] bridge0: port 1(bridge_slave_0) entered blocking state [ 5301.085531] bridge0: port 1(bridge_slave_0) entered disabled state [ 5301.085588] bridge_slave_0: entered allmulticast mode [ 5301.085800] bridge_slave_0: entered promiscuous mode [ 5301.095617] bridge0: port 1(bridge_slave_0) entered blocking state [ 5301.095633] bridge0: port 1(bridge_slave_0) entered disabled state … [ 5301.149734] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 5301.173234] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 5301.180517] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 5301.193481] hsr_slave_0: entered promiscuous mode [ 5301.204425] hsr_slave_1: entered promiscuous mode [ 5301.210172] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.210185] Cannot create hsr debugfs directory [ 5301.224061] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 5301.246901] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 5301.255934] team0: Port device team_slave_0 added [ 5301.256480] team0: Port device team_slave_1 added [ 5301.256948] team0: Port device team_slave_0 added … [ 5301.435928] hsr_slave_0: entered promiscuous mode [ 5301.446029] hsr_slave_1: entered promiscuous mode [ 5301.455872] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.455884] Cannot create hsr debugfs directory [ 5301.502664] hsr_slave_0: entered promiscuous mode [ 5301.513675] hsr_slave_1: entered promiscuous mode [ 5301.526155] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.526164] Cannot create hsr debugfs directory [ 5301.563662] hsr_slave_0: entered promiscuous mode [ 5301.576129] hsr_slave_1: entered promiscuous mode [ 5301.580259] debugfs: Directory 'hsr0' with parent 'hsr' already present! [ 5301.580270] Cannot create hsr debugfs directory [ 5301.590269] 8021q: adding VLAN 0 to HW filter on device bond0 [ 5301.595872] KASAN: null-ptr-deref in range [0x0000000000000130-0x0000000000000137] [ 5301.595877] Mem abort info: [ 5301.595881] ESR = 0x0000000096000006 [ 5301.595885] EC = 0x25: DABT (current EL), IL = 32 bits [ 5301.595889] SET = 0, FnV = 0 [ 5301.595893] EA = 0, S1PTW = 0 [ 5301.595896] FSC = 0x06: level 2 translation fault [ 5301.595900] Data abort info: [ 5301.595903] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 [ 5301.595907] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 5301.595911] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 5301.595915] [dfff800000000026] address between user and kernel address ranges [ 5301.595971] Internal error: Oops: 0000000096000006 [#1] SMP … [ 5301.596076] CPU: 2 PID: 102769 Comm: syz-executor.3 Kdump: loaded Tainted: G W ------- --- 6.10.0-0.rc2.20240608gitdc772f8237f9.29.fc41.aarch64+debug #1 [ 5301.596080] Hardware name: VMware, Inc. VMware20,1/VBSA, BIOS VMW201.00V.21805430.BA64.2305221830 05/22/2023 [ 5301.596082] pstate: 01400005 (nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 5301.596085] pc : strnlen+0x40/0x88 [ 5301.596114] lr : trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 [ 5301.596124] sp : ffff8000beef6b40 [ 5301.596126] x29: ffff8000beef6b40 x28: dfff800000000000 x27: 0000000000000001 [ 5301.596131] x26: 6de1800082c62bd0 x25: 1ffff000110aa9e0 x24: ffff800088554f00 [ 5301.596136] x23: ffff800088554ec0 x22: 0000000000000130 x21: 0000000000000140 [ 5301.596140] x20: dfff800000000000 x19: ffff8000beef6c60 x18: ffff7000115106d8 [ 5301.596143] x17: ffff800121bad000 x16: ffff800080020000 x15: 0000000000000006 [ 5301.596147] x14: 0000000000000002 x13: ffff0001f3ed8d14 x12: ffff700017ddeda5 [ 5301.596151] x11: 1ffff00017ddeda4 x10: ffff700017ddeda4 x9 : ffff800082cc5eec [ 5301.596155] x8 : 0000000000000004 x7 : 00000000f1f1f1f1 x6 : 00000000f2f2f200 [ 5301.596158] x5 : 00000000f3f3f3f3 x4 : ffff700017dded80 x3 : 00000000f204f1f1 [ 5301.596162] x2 : 0000000000000026 x1 : 0000000000000000 x0 : 0000000000000130 [ 5301.596166] Call trace: [ 5301.596175] strnlen+0x40/0x88 [ 5301.596179] trace_event_get_offsets_qdisc_reset+0x6c/0x2b0 [ 5301.596182] perf_trace_qdisc_reset+0xb0/0x538 [ 5301.596184] __traceiter_qdisc_reset+0x68/0xc0 [ 5301.596188] qdisc_reset+0x43c/0x5e8 [ 5301.596190] netif_set_real_num_tx_queues+0x288/0x770 [ 5301.596194] veth_init_queues+0xfc/0x130 [veth] [ 5301.596198] veth_newlink+0x45c/0x850 [veth] [ 5301.596202] rtnl_newlink_create+0x2c8/0x798 [ 5301.596205] __rtnl_newlink+0x92c/0xb60 [ 5301.596208] rtnl_newlink+0xd8/0x130 [ 5301.596211] rtnetlink_rcv_msg+0x2e0/0x890 [ 5301.596214] netlink_rcv_skb+0x1c4/0x380 [ 5301.596225] rtnetlink_rcv+0x20/0x38 [ 5301.596227] netlink_unicast+0x3c8/0x640 [ 5301.596231] netlink_sendmsg+0x658/0xa60 [ 5301.596234] __sock_sendmsg+0xd0/0x180 [ 5301.596243] __sys_sendto+0x1c0/0x280 [ 5301.596246] __arm64_sys_sendto+0xc8/0x150 [ 5301.596249] invoke_syscall+0xdc/0x268 [ 5301.596256] el0_svc_common.constprop.0+0x16c/0x240 [ 5301.596259] do_el0_svc+0x48/0x68 [ 5301.596261] el0_svc+0x50/0x188 [ 5301.596265] el0t_64_sync_handler+0x120/0x130 [ 5301.596268] el0t_64_sync+0x194/0x198 [ 5301.596272] Code: eb15001f 54000120 d343fc02 12000801 (38f46842) [ 5301.596285] SMP: stopping secondary CPUs [ 5301.597053] Starting crashdump kernel... [ 5301.597057] Bye! After applying our patch, I didn't find any kernel panic errors. We've found a simple reproducer # echo 1 > /sys/kernel/debug/tracing/events/qdisc/qdisc_reset/enable # ip link add veth0 type veth peer name veth1 Error: Unknown device type. However, without our patch applied, I tested upstream 6.10.0-rc3 kernel using the qdisc_reset event and the ip command on my qemu virtual machine. This 2 commands makes always kernel panic. Linux version: 6.10.0-rc3 [ 0.000000] Linux version 6.10.0-rc3-00164-g44ef20baed8e-dirty (paran@fedora) (gcc (GCC) 14.1.1 20240522 (Red Hat 14.1.1-4), GNU ld version 2.41-34.fc40) #20 SMP PREEMPT Sat Jun 15 16:51:25 KST 2024 Kernel panic message: [ 615.236484] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP [ 615.237250] Dumping ftrace buffer: [ 615.237679] (ftrace buffer empty) [ 615.238097] Modules linked in: veth crct10dif_ce virtio_gpu virtio_dma_buf drm_shmem_helper drm_kms_helper zynqmp_fpga xilinx_can xilinx_spi xilinx_selectmap xilinx_core xilinx_pr_decoupler versal_fpga uvcvideo uvc videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videodev videobuf2_common mc usbnet deflate zstd ubifs ubi rcar_canfd rcar_can omap_mailbox ntb_msi_test ntb_hw_epf lattice_sysconfig_spi lattice_sysconfig ice40_spi gpio_xilinx dwmac_altr_socfpga mdio_regmap stmmac_platform stmmac pcs_xpcs dfl_fme_region dfl_fme_mgr dfl_fme_br dfl_afu dfl fpga_region fpga_bridge can can_dev br_netfilter bridge stp llc atl1c ath11k_pci mhi ath11k_ahb ath11k qmi_helpers ath10k_sdio ath10k_pci ath10k_core ath mac80211 libarc4 cfg80211 drm fuse backlight ipv6 Jun 22 02:36:5[3 6k152.62-4sm98k4-0k]v kCePUr:n e1l :P IUDn:a b4le6 8t oC ohmma: nidpl eN oketr nteali nptaedg i6n.g1 0re.0q-urecs3t- 0at0 1v6i4r-tgu4a4le fa2d0dbraeeds0se-dir tyd f#f2f08 615.252376] Hardware name: linux,dummy-virt (DT) [ 615.253220] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 615.254433] pc : strnlen+0x6c/0xe0 [ 615.255096] lr : trace_event_get_offsets_qdisc_reset+0x94/0x3d0 [ 615.256088] sp : ffff800080b269a0 [ 615.256615] x29: ffff800080b269a0 x28: ffffc070f3f98500 x27: 0000000000000001 [ 615.257831] x26: 0000000000000010 x25: ffffc070f3f98540 x24: ffffc070f619cf60 [ 615.259020] x23: 0000000000000128 x22: 0000000000000138 x21: dfff800000000000 [ 615.260241] x20: ffffc070f631ad00 x19: 0000000000000128 x18: ffffc070f448b800 [ 615.261454] x17: 0000000000000000 x16: 0000000000000001 x15: ffffc070f4ba2a90 [ 615.262635] x14: ffff700010164d73 x13: 1ffff80e1e8d5eb3 x12: 1ffff00010164d72 [ 615.263877] x11: ffff700010164d72 x10: dfff800000000000 x9 : ffffc070e85d6184 [ 615.265047] x8 : ffffc070e4402070 x7 : 000000000000f1f1 x6 : 000000001504a6d3 [ 615.266336] x5 : ffff28ca21122140 x4 : ffffc070f5043ea8 x3 : 0000000000000000 [ 615.267528] x2 : 0000000000000025 x1 : 0000000000000000 x0 : 0000000000000000 [ 615.268747] Call trace: [ 615.269180] strnlen+0x6c/0xe0 [ 615.269767] trace_event_get_offsets_qdisc_reset+0x94/0x3d0 [ 615.270716] trace_event_raw_event_qdisc_reset+0xe8/0x4e8 [ 615.271667] __traceiter_qdisc_reset+0xa0/0x140 [ 615.272499] qdisc_reset+0x554/0x848 [ 615.273134] netif_set_real_num_tx_queues+0x360/0x9a8 [ 615.274050] veth_init_queues+0x110/0x220 [veth] [ 615.275110] veth_newlink+0x538/0xa50 [veth] [ 615.276172] __rtnl_newlink+0x11e4/0x1bc8 [ 615.276944] rtnl_newlink+0xac/0x120 [ 615.277657] rtnetlink_rcv_msg+0x4e4/0x1370 [ 615.278409] netlink_rcv_skb+0x25c/0x4f0 [ 615.279122] rtnetlink_rcv+0x48/0x70 [ 615.279769] netlink_unicast+0x5a8/0x7b8 [ 615.280462] netlink_sendmsg+0xa70/0x1190 Yeoreum and I don't know if the patch we wrote will fix the underlying cause, but we think that priority is to prevent kernel panic happening. So, we're sending this patch. Fixes: 51270d5 ("tracing/net_sched: Fix tracepoints that save qdisc_dev() as a string") Link: https://lore.kernel.org/lkml/[email protected]/t/ Cc: [email protected] Tested-by: Yunseong Kim <[email protected]> Signed-off-by: Yunseong Kim <[email protected]> Signed-off-by: Yeoreum Yun <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Abeni <[email protected]>
The RISC-V kernel already has checks to ensure that memory which would lie outside of the linear mapping is not used. However those checks use memory_limit, which is used to implement the mem= kernel command line option (to limit the total amount of memory, not its address range). When memory is made up of two or more non-contiguous memory banks this check is incorrect. Two changes are made here: - add a call in setup_bootmem() to memblock_cap_memory_range() which will cause any memory which falls outside the linear mapping to be removed from the memory regions. - remove the check in create_linear_mapping_page_table() which was intended to remove memory which is outside the liner mapping based on memory_limit, as it is no longer needed. Note a check for mapping more memory than memory_limit (to implement mem=) is unnecessary because of the existing call to memblock_enforce_memory_limit(). This issue was seen when booting on a SV39 platform with two memory banks: 0x00,80000000 1GiB 0x20,00000000 32GiB This memory range is 158GiB from top to bottom, but the linear mapping is limited to 128GiB, so the lower block of RAM will be mapped at PAGE_OFFSET, and the upper block straddles the top of the linear mapping. This causes the following Oops: [ 0.000000] Linux version 6.10.0-rc2-gd3b8dd5b51dd-dirty ([email protected]) (riscv64-codasip-linux-gcc (GCC) 13.2.0, GNU ld (GNU Binutils) 2.41.0.20231213) #20 SMP Sat Jun 22 11:34:22 BST 2024 [ 0.000000] memblock_add: [0x0000000080000000-0x00000000bfffffff] early_init_dt_add_memory_arch+0x4a/0x52 [ 0.000000] memblock_add: [0x0000002000000000-0x00000027ffffffff] early_init_dt_add_memory_arch+0x4a/0x52 ... [ 0.000000] memblock_alloc_try_nid: 23724 bytes align=0x8 nid=-1 from=0x0000000000000000 max_addr=0x0000000000000000 early_init_dt_alloc_memory_arch+0x1e/0x48 [ 0.000000] memblock_reserve: [0x00000027ffff5350-0x00000027ffffaffb] memblock_alloc_range_nid+0xb8/0x132 [ 0.000000] Unable to handle kernel paging request at virtual address fffffffe7fff5350 [ 0.000000] Oops [#1] [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.10.0-rc2-gd3b8dd5b51dd-dirty #20 [ 0.000000] Hardware name: codasip,a70x (DT) [ 0.000000] epc : __memset+0x8c/0x104 [ 0.000000] ra : memblock_alloc_try_nid+0x74/0x84 [ 0.000000] epc : ffffffff805e88c8 ra : ffffffff806148f6 sp : ffffffff80e03d50 [ 0.000000] gp : ffffffff80ec4158 tp : ffffffff80e0bec0 t0 : fffffffe7fff52f8 [ 0.000000] t1 : 00000027ffffb000 t2 : 5f6b636f6c626d65 s0 : ffffffff80e03d90 [ 0.000000] s1 : 0000000000005cac a0 : fffffffe7fff5350 a1 : 0000000000000000 [ 0.000000] a2 : 0000000000005cac a3 : fffffffe7fffaff8 a4 : 000000000000002c [ 0.000000] a5 : ffffffff805e88c8 a6 : 0000000000005cac a7 : 0000000000000030 [ 0.000000] s2 : fffffffe7fff5350 s3 : ffffffffffffffff s4 : 0000000000000000 [ 0.000000] s5 : ffffffff8062347e s6 : 0000000000000000 s7 : 0000000000000001 [ 0.000000] s8 : 0000000000002000 s9 : 00000000800226d0 s10: 0000000000000000 [ 0.000000] s11: 0000000000000000 t3 : ffffffff8080a928 t4 : ffffffff8080a928 [ 0.000000] t5 : ffffffff8080a928 t6 : ffffffff8080a940 [ 0.000000] status: 0000000200000100 badaddr: fffffffe7fff5350 cause: 000000000000000f [ 0.000000] [<ffffffff805e88c8>] __memset+0x8c/0x104 [ 0.000000] [<ffffffff8062349c>] early_init_dt_alloc_memory_arch+0x1e/0x48 [ 0.000000] [<ffffffff8043e892>] __unflatten_device_tree+0x52/0x114 [ 0.000000] [<ffffffff8062441e>] unflatten_device_tree+0x9e/0xb8 [ 0.000000] [<ffffffff806046fe>] setup_arch+0xd4/0x5bc [ 0.000000] [<ffffffff806007aa>] start_kernel+0x76/0x81a [ 0.000000] Code: b823 02b2 bc23 02b2 b023 04b2 b423 04b2 b823 04b2 (bc23) 04b2 [ 0.000000] ---[ end trace 0000000000000000 ]--- [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! [ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- The problem is that memblock (unaware that some physical memory cannot be used) has allocated memory from the top of memory but which is outside the linear mapping region. Signed-off-by: Stuart Menefy <[email protected]> Fixes: c99127c ("riscv: Make sure the linear mapping does not use the kernel mapping") Reviewed-by: David McKay <[email protected]> Reviewed-by: Alexandre Ghiti <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
…s_lock For storing a value to a queue attribute, the queue_attr_store function first freezes the queue (->q_usage_counter(io)) and then acquire ->sysfs_lock. This seems not correct as the usual ordering should be to acquire ->sysfs_lock before freezing the queue. This incorrect ordering causes the following lockdep splat which we are able to reproduce always simply by accessing /sys/kernel/debug file using ls command: [ 57.597146] WARNING: possible circular locking dependency detected [ 57.597154] 6.12.0-10553-gb86545e02e8c #20 Tainted: G W [ 57.597162] ------------------------------------------------------ [ 57.597168] ls/4605 is trying to acquire lock: [ 57.597176] c00000003eb56710 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0 [ 57.597200] but task is already holding lock: [ 57.597207] c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4 [ 57.597226] which lock already depends on the new lock. [ 57.597233] the existing dependency chain (in reverse order) is: [ 57.597241] -> #5 (&sb->s_type->i_mutex_key#3){++++}-{4:4}: [ 57.597255] down_write+0x6c/0x18c [ 57.597264] start_creating+0xb4/0x24c [ 57.597274] debugfs_create_dir+0x2c/0x1e8 [ 57.597283] blk_register_queue+0xec/0x294 [ 57.597292] add_disk_fwnode+0x2e4/0x548 [ 57.597302] brd_alloc+0x2c8/0x338 [ 57.597309] brd_init+0x100/0x178 [ 57.597317] do_one_initcall+0x88/0x3e4 [ 57.597326] kernel_init_freeable+0x3cc/0x6e0 [ 57.597334] kernel_init+0x34/0x1cc [ 57.597342] ret_from_kernel_user_thread+0x14/0x1c [ 57.597350] -> #4 (&q->debugfs_mutex){+.+.}-{4:4}: [ 57.597362] __mutex_lock+0xfc/0x12a0 [ 57.597370] blk_register_queue+0xd4/0x294 [ 57.597379] add_disk_fwnode+0x2e4/0x548 [ 57.597388] brd_alloc+0x2c8/0x338 [ 57.597395] brd_init+0x100/0x178 [ 57.597402] do_one_initcall+0x88/0x3e4 [ 57.597410] kernel_init_freeable+0x3cc/0x6e0 [ 57.597418] kernel_init+0x34/0x1cc [ 57.597426] ret_from_kernel_user_thread+0x14/0x1c [ 57.597434] -> #3 (&q->sysfs_lock){+.+.}-{4:4}: [ 57.597446] __mutex_lock+0xfc/0x12a0 [ 57.597454] queue_attr_store+0x9c/0x110 [ 57.597462] sysfs_kf_write+0x70/0xb0 [ 57.597471] kernfs_fop_write_iter+0x1b0/0x2ac [ 57.597480] vfs_write+0x3dc/0x6e8 [ 57.597488] ksys_write+0x84/0x140 [ 57.597495] system_call_exception+0x130/0x360 [ 57.597504] system_call_common+0x160/0x2c4 [ 57.597516] -> #2 (&q->q_usage_counter(io)#21){++++}-{0:0}: [ 57.597530] __submit_bio+0x5ec/0x828 [ 57.597538] submit_bio_noacct_nocheck+0x1e4/0x4f0 [ 57.597547] iomap_readahead+0x2a0/0x448 [ 57.597556] xfs_vm_readahead+0x28/0x3c [ 57.597564] read_pages+0x88/0x41c [ 57.597571] page_cache_ra_unbounded+0x1ac/0x2d8 [ 57.597580] filemap_get_pages+0x188/0x984 [ 57.597588] filemap_read+0x13c/0x4bc [ 57.597596] xfs_file_buffered_read+0x88/0x17c [ 57.597605] xfs_file_read_iter+0xac/0x158 [ 57.597614] vfs_read+0x2d4/0x3b4 [ 57.597622] ksys_read+0x84/0x144 [ 57.597629] system_call_exception+0x130/0x360 [ 57.597637] system_call_common+0x160/0x2c4 [ 57.597647] -> #1 (mapping.invalidate_lock#2){++++}-{4:4}: [ 57.597661] down_read+0x6c/0x220 [ 57.597669] filemap_fault+0x870/0x100c [ 57.597677] xfs_filemap_fault+0xc4/0x18c [ 57.597684] __do_fault+0x64/0x164 [ 57.597693] __handle_mm_fault+0x1274/0x1dac [ 57.597702] handle_mm_fault+0x248/0x484 [ 57.597711] ___do_page_fault+0x428/0xc0c [ 57.597719] hash__do_page_fault+0x30/0x68 [ 57.597727] do_hash_fault+0x90/0x35c [ 57.597736] data_access_common_virt+0x210/0x220 [ 57.597745] _copy_from_user+0xf8/0x19c [ 57.597754] sel_write_load+0x178/0xd54 [ 57.597762] vfs_write+0x108/0x6e8 [ 57.597769] ksys_write+0x84/0x140 [ 57.597777] system_call_exception+0x130/0x360 [ 57.597785] system_call_common+0x160/0x2c4 [ 57.597794] -> #0 (&mm->mmap_lock){++++}-{4:4}: [ 57.597806] __lock_acquire+0x17cc/0x2330 [ 57.597814] lock_acquire+0x138/0x400 [ 57.597822] __might_fault+0x7c/0xc0 [ 57.597830] filldir64+0xe8/0x390 [ 57.597839] dcache_readdir+0x80/0x2d4 [ 57.597846] iterate_dir+0xd8/0x1d4 [ 57.597855] sys_getdents64+0x88/0x2d4 [ 57.597864] system_call_exception+0x130/0x360 [ 57.597872] system_call_common+0x160/0x2c4 [ 57.597881] other info that might help us debug this: [ 57.597888] Chain exists of: &mm->mmap_lock --> &q->debugfs_mutex --> &sb->s_type->i_mutex_key#3 [ 57.597905] Possible unsafe locking scenario: [ 57.597911] CPU0 CPU1 [ 57.597917] ---- ---- [ 57.597922] rlock(&sb->s_type->i_mutex_key#3); [ 57.597932] lock(&q->debugfs_mutex); [ 57.597940] lock(&sb->s_type->i_mutex_key#3); [ 57.597950] rlock(&mm->mmap_lock); [ 57.597958] *** DEADLOCK *** [ 57.597965] 2 locks held by ls/4605: [ 57.597971] #0: c0000000137c12f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154 [ 57.597989] #1: c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4 Prevent the above lockdep warning by acquiring ->sysfs_lock before freezing the queue while storing a queue attribute in queue_attr_store function. Later, we also found[1] another function __blk_mq_update_nr_ hw_queues where we first freeze queue and then acquire the ->sysfs_lock. So we've also updated lock ordering in __blk_mq_update_nr_hw_queues function and ensured that in all code paths we follow the correct lock ordering i.e. acquire ->sysfs_lock before freezing the queue. [1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/ Reported-by: [email protected] Fixes: af28141 ("block: freeze the queue in queue_attr_store") Tested-by: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Nilay Shroff <[email protected]> Reviewed-by: Ming Lei <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
When including the rust_example driver (not as module) I get a kernel panic:
Config and kernel console here: https://gist.github.com/Kloenk/aad17db1adc313ec49a51712c03060b0
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