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ARM: dts: Add support for Olimex AM3352-SOM (2) #53

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vinifr
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@vinifr vinifr commented Dec 9, 2015

Add a dts file for Olimex AM3352-SOM board. The board does not use the PMIC
tps65217 and does not have many peripherals present in beaglebone. Thus, a
specific dtsi file (am335x-som-common.dtsi) is needed.

Signed-off-by: Dimitar Gamishev [email protected]
Signed-off-by: Vinicius Maciel [email protected]

RobertCNelson added a commit to RobertCNelson/ti-linux-kernel-dev that referenced this pull request Dec 9, 2015
RobertCNelson added a commit to RobertCNelson/ti-linux-kernel-dev that referenced this pull request Dec 9, 2015
Add a dts file for Olimex AM3352-SOM board. The board does not use the PMIC
tps65217 and does not have many peripherals present in beaglebone. Thus, a
specific dtsi file (am335x-som-common.dtsi) is needed.

Signed-off-by: Dimitar Gamishev <[email protected]>
Signed-off-by: Vinicius Maciel <[email protected]>
@vinifr
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vinifr commented Dec 9, 2015

Hi, you are right
I removed "ti,am335x-bone" and tested, no phy_mask duplicated.

davinci_mdio 4a101000.mdio: detected phy mask fffffffc
libphy: 4a101000.mdio: probed
davinci_mdio 4a101000.mdio: phy[0]: device 4a101000.mdio:00, driver SMSC LAN8710/LAN8720
davinci_mdio 4a101000.mdio: phy[1]: device 4a101000.mdio:01, driver SMSC LAN8710/LAN8720

@RobertCNelson
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Nope, that's exactly what we want to see. ;)

davinci_mdio 4a101000.mdio: detected phy mask fffffffc
libphy: 4a101000.mdio: probed
davinci_mdio 4a101000.mdio: phy[0]: device 4a101000.mdio:00, driver SMSC LAN8710/LAN8720
davinci_mdio 4a101000.mdio: phy[1]: device 4a101000.mdio:01, driver SMSC LAN8710/LAN8720

For this board (with dual ethernet ports), we don't want to modify the dt values as was shown previously:

davinci_mdio: dt: updated phy_id[0] from phy_mask[fffffffc]
davinci_mdio: dt: updated phy_id[1] from phy_mask[fffffffc]

@vinifr
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vinifr commented Dec 9, 2015

Good. So now everything is apparently okay, right? If so, what happens next? Sorry, i'm a noob :D. There is a thing like 'next merge window'?

@RobertCNelson
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it'll get pushed out on Thursday as "r36" built on/for:

debian: wheezy/jessie/stretch/sid
ubuntu: trusty/vivid/wily/xenial

To install it:

sudo apt-get update
sudo apt-get install linux-image-4.1.13-ti-r36
or
sudo apt-get install linux-image-4.1.13-ti-rt-r36
sudo reboot

Might even get 4.1.14 too... but we will see..

thess pushed a commit to thess/ti-linux-kernel-dev that referenced this pull request Dec 10, 2015
RobertCNelson pushed a commit that referenced this pull request Apr 26, 2017
commit 6f6266a upstream.

Reserving a runtime region results in splitting the EFI memory
descriptors for the runtime region. This results in runtime region
descriptors with bogus memory mappings, leading to interesting crashes
like the following during a kexec:

  general protection fault: 0000 [#1] SMP
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1 #53
  Hardware name: Wiwynn Leopard-Orv2/Leopard-DDR BW, BIOS LBM05   09/30/2016
  RIP: 0010:virt_efi_set_variable()
  ...
  Call Trace:
   efi_delete_dummy_variable()
   efi_enter_virtual_mode()
   start_kernel()
   ? set_init_arg()
   x86_64_start_reservations()
   x86_64_start_kernel()
   start_cpu()
  ...
  Kernel panic - not syncing: Fatal exception

Runtime regions will not be freed and do not need to be reserved, so
skip the memmap modification in this case.

Signed-off-by: Omar Sandoval <[email protected]>
Signed-off-by: Matt Fleming <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Jones <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: 8e80632 ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
crow-misia pushed a commit to crow-misia/linux that referenced this pull request Feb 16, 2019
[ Upstream commit 6fa19f5 ]

syzbot was able to catch a bug in rds [1]

The issue here is that the socket might be found in a hash table
but that its refcount has already be set to 0 by another cpu.

We need to use refcount_inc_not_zero() to be safe here.

[1]

refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 23129 at lib/refcount.c:153 refcount_inc_checked lib/refcount.c:153 [inline]
WARNING: CPU: 1 PID: 23129 at lib/refcount.c:153 refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 23129 Comm: syz-executor3 Not tainted 5.0.0-rc4+ beagleboard#53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 panic+0x2cb/0x65c kernel/panic.c:214
 __warn.cold+0x20/0x48 kernel/panic.c:571
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:refcount_inc_checked lib/refcount.c:153 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Code: 1d 51 63 c8 06 31 ff 89 de e8 eb 1b f2 fd 84 db 75 dd e8 a2 1a f2 fd 48 c7 c7 60 9f 81 88 c6 05 31 63 c8 06 01 e8 af 65 bb fd <0f> 0b eb c1 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 49
RSP: 0018:ffff8880a0cbf1e8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90006113000
RDX: 000000000001047d RSI: ffffffff81685776 RDI: 0000000000000005
RBP: ffff8880a0cbf1f8 R08: ffff888097c9e100 R09: ffffed1015ce5021
R10: ffffed1015ce5020 R11: ffff8880ae728107 R12: ffff8880723c20c0
R13: ffff8880723c24b0 R14: dffffc0000000000 R15: ffffed1014197e64
 sock_hold include/net/sock.h:647 [inline]
 rds_sock_addref+0x19/0x20 net/rds/af_rds.c:675
 rds_find_bound+0x97c/0x1080 net/rds/bind.c:82
 rds_recv_incoming+0x3be/0x1430 net/rds/recv.c:362
 rds_loop_xmit+0xf3/0x2a0 net/rds/loop.c:96
 rds_send_xmit+0x1355/0x2a10 net/rds/send.c:355
 rds_sendmsg+0x323c/0x44e0 net/rds/send.c:1368
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 __sys_sendto+0x387/0x5f0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto net/socket.c:1796 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458089
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc266df8c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000458089
RDX: 0000000000000000 RSI: 00000000204b3fff RDI: 0000000000000005
RBP: 000000000073bf00 R08: 00000000202b4000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc266df96d4
R13: 00000000004c56e4 R14: 00000000004d94a8 R15: 00000000ffffffff

Fixes: cc4dfb7 ("rds: fix two RCU related problems")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: syzbot <[email protected]>
Cc: Sowmini Varadhan <[email protected]>
Cc: Santosh Shilimkar <[email protected]>
Cc: [email protected]
Cc: Cong Wang <[email protected]>
Acked-by: Santosh Shilimkar <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
crow-misia pushed a commit to crow-misia/linux that referenced this pull request Feb 16, 2019
commit 70ed714 upstream.

KASAN detects a use-after-free when vop devices are removed.

This problem was introduced by commit 0063e8b ("virtio_vop:
don't kfree device on register failure").  That patch moved the freeing
of the struct _vop_vdev to the release function, but failed to ensure
that vop holds a reference to the device when it doesn't want it to go
away.  A kfree() was replaced with a put_device() in the unregistration
path, but the last reference to the device is already dropped in
unregister_virtio_device() so the struct is freed before vop is done
with it.

Fix it by holding a reference until cleanup is done.  This is similar to
the fix in virtio_pci in commit 2989be0 ("virtio_pci: fix use
after free on release").

 ==================================================================
 BUG: KASAN: use-after-free in vop_scan_devices+0xc6c/0xe50 [vop]
 Read of size 8 at addr ffff88800da18580 by task kworker/0:1/12

 CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.0.0-rc4+ beagleboard#53
 Workqueue: events vop_hotplug_devices [vop]
 Call Trace:
  dump_stack+0x74/0xbb
  print_address_description+0x5d/0x2b0
  ? vop_scan_devices+0xc6c/0xe50 [vop]
  kasan_report+0x152/0x1aa
  ? vop_scan_devices+0xc6c/0xe50 [vop]
  ? vop_scan_devices+0xc6c/0xe50 [vop]
  vop_scan_devices+0xc6c/0xe50 [vop]
  ? vop_loopback_free_irq+0x160/0x160 [vop_loopback]
  process_one_work+0x7c0/0x14b0
  ? pwq_dec_nr_in_flight+0x2d0/0x2d0
  ? do_raw_spin_lock+0x120/0x280
  worker_thread+0x8f/0xbf0
  ? __kthread_parkme+0x78/0xf0
  ? process_one_work+0x14b0/0x14b0
  kthread+0x2ae/0x3a0
  ? kthread_park+0x120/0x120
  ret_from_fork+0x3a/0x50

 Allocated by task 12:
  kmem_cache_alloc_trace+0x13a/0x2a0
  vop_scan_devices+0x473/0xe50 [vop]
  process_one_work+0x7c0/0x14b0
  worker_thread+0x8f/0xbf0
  kthread+0x2ae/0x3a0
  ret_from_fork+0x3a/0x50

 Freed by task 12:
  kfree+0x104/0x310
  device_release+0x73/0x1d0
  kobject_put+0x14f/0x420
  unregister_virtio_device+0x32/0x50
  vop_scan_devices+0x19d/0xe50 [vop]
  process_one_work+0x7c0/0x14b0
  worker_thread+0x8f/0xbf0
  kthread+0x2ae/0x3a0
  ret_from_fork+0x3a/0x50

 The buggy address belongs to the object at ffff88800da18008
  which belongs to the cache kmalloc-2k of size 2048
 The buggy address is located 1400 bytes inside of
  2048-byte region [ffff88800da18008, ffff88800da18808)
 The buggy address belongs to the page:
 page:ffffea0000368600 count:1 mapcount:0 mapping:ffff88801440dbc0 index:0x0 compound_mapcount: 0
 flags: 0x4000000000010200(slab|head)
 raw: 4000000000010200 ffffea0000378608 ffffea000037a008 ffff88801440dbc0
 raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff88800da18480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff88800da18500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 >ffff88800da18580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                    ^
  ffff88800da18600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff88800da18680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ==================================================================

Fixes: 0063e8b ("virtio_vop: don't kfree device on register failure")
Signed-off-by: Vincent Whitchurch <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
RobertCNelson pushed a commit that referenced this pull request Mar 18, 2019
[ Upstream commit 6fa19f5 ]

syzbot was able to catch a bug in rds [1]

The issue here is that the socket might be found in a hash table
but that its refcount has already be set to 0 by another cpu.

We need to use refcount_inc_not_zero() to be safe here.

[1]

refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 23129 at lib/refcount.c:153 refcount_inc_checked lib/refcount.c:153 [inline]
WARNING: CPU: 1 PID: 23129 at lib/refcount.c:153 refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 23129 Comm: syz-executor3 Not tainted 5.0.0-rc4+ #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 panic+0x2cb/0x65c kernel/panic.c:214
 __warn.cold+0x20/0x48 kernel/panic.c:571
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:refcount_inc_checked lib/refcount.c:153 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:151
Code: 1d 51 63 c8 06 31 ff 89 de e8 eb 1b f2 fd 84 db 75 dd e8 a2 1a f2 fd 48 c7 c7 60 9f 81 88 c6 05 31 63 c8 06 01 e8 af 65 bb fd <0f> 0b eb c1 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 49
RSP: 0018:ffff8880a0cbf1e8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90006113000
RDX: 000000000001047d RSI: ffffffff81685776 RDI: 0000000000000005
RBP: ffff8880a0cbf1f8 R08: ffff888097c9e100 R09: ffffed1015ce5021
R10: ffffed1015ce5020 R11: ffff8880ae728107 R12: ffff8880723c20c0
R13: ffff8880723c24b0 R14: dffffc0000000000 R15: ffffed1014197e64
 sock_hold include/net/sock.h:647 [inline]
 rds_sock_addref+0x19/0x20 net/rds/af_rds.c:675
 rds_find_bound+0x97c/0x1080 net/rds/bind.c:82
 rds_recv_incoming+0x3be/0x1430 net/rds/recv.c:362
 rds_loop_xmit+0xf3/0x2a0 net/rds/loop.c:96
 rds_send_xmit+0x1355/0x2a10 net/rds/send.c:355
 rds_sendmsg+0x323c/0x44e0 net/rds/send.c:1368
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:631
 __sys_sendto+0x387/0x5f0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto net/socket.c:1796 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458089
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc266df8c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000458089
RDX: 0000000000000000 RSI: 00000000204b3fff RDI: 0000000000000005
RBP: 000000000073bf00 R08: 00000000202b4000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc266df96d4
R13: 00000000004c56e4 R14: 00000000004d94a8 R15: 00000000ffffffff

Fixes: cc4dfb7 ("rds: fix two RCU related problems")
Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: syzbot <[email protected]>
Cc: Sowmini Varadhan <[email protected]>
Cc: Santosh Shilimkar <[email protected]>
Cc: [email protected]
Cc: Cong Wang <[email protected]>
Acked-by: Santosh Shilimkar <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
RobertCNelson pushed a commit that referenced this pull request May 9, 2020
commit 351cbf6 upstream.

Zygo reported the following lockdep splat while testing the balance
patches

======================================================
WARNING: possible circular locking dependency detected
5.6.0-c6f0579d496a+ #53 Not tainted
------------------------------------------------------
kswapd0/1133 is trying to acquire lock:
ffff888092f622c0 (&delayed_node->mutex){+.+.}, at: __btrfs_release_delayed_node+0x7c/0x5b0

but task is already holding lock:
ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}:
       fs_reclaim_acquire.part.91+0x29/0x30
       fs_reclaim_acquire+0x19/0x20
       kmem_cache_alloc_trace+0x32/0x740
       add_block_entry+0x45/0x260
       btrfs_ref_tree_mod+0x6e2/0x8b0
       btrfs_alloc_tree_block+0x789/0x880
       alloc_tree_block_no_bg_flush+0xc6/0xf0
       __btrfs_cow_block+0x270/0x940
       btrfs_cow_block+0x1ba/0x3a0
       btrfs_search_slot+0x999/0x1030
       btrfs_insert_empty_items+0x81/0xe0
       btrfs_insert_delayed_items+0x128/0x7d0
       __btrfs_run_delayed_items+0xf4/0x2a0
       btrfs_run_delayed_items+0x13/0x20
       btrfs_commit_transaction+0x5cc/0x1390
       insert_balance_item.isra.39+0x6b2/0x6e0
       btrfs_balance+0x72d/0x18d0
       btrfs_ioctl_balance+0x3de/0x4c0
       btrfs_ioctl+0x30ab/0x44a0
       ksys_ioctl+0xa1/0xe0
       __x64_sys_ioctl+0x43/0x50
       do_syscall_64+0x77/0x2c0
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&delayed_node->mutex){+.+.}:
       __lock_acquire+0x197e/0x2550
       lock_acquire+0x103/0x220
       __mutex_lock+0x13d/0xce0
       mutex_lock_nested+0x1b/0x20
       __btrfs_release_delayed_node+0x7c/0x5b0
       btrfs_remove_delayed_node+0x49/0x50
       btrfs_evict_inode+0x6fc/0x900
       evict+0x19a/0x2c0
       dispose_list+0xa0/0xe0
       prune_icache_sb+0xbd/0xf0
       super_cache_scan+0x1b5/0x250
       do_shrink_slab+0x1f6/0x530
       shrink_slab+0x32e/0x410
       shrink_node+0x2a5/0xba0
       balance_pgdat+0x4bd/0x8a0
       kswapd+0x35a/0x800
       kthread+0x1e9/0x210
       ret_from_fork+0x3a/0x50

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(fs_reclaim);
                               lock(&delayed_node->mutex);
                               lock(fs_reclaim);
  lock(&delayed_node->mutex);

 *** DEADLOCK ***

3 locks held by kswapd0/1133:
 #0: ffffffff8fc5f860 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30
 #1: ffffffff8fc380d8 (shrinker_rwsem){++++}, at: shrink_slab+0x1e8/0x410
 #2: ffff8881e0e6c0e8 (&type->s_umount_key#42){++++}, at: trylock_super+0x1b/0x70

stack backtrace:
CPU: 2 PID: 1133 Comm: kswapd0 Not tainted 5.6.0-c6f0579d496a+ #53
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 dump_stack+0xc1/0x11a
 print_circular_bug.isra.38.cold.57+0x145/0x14a
 check_noncircular+0x2a9/0x2f0
 ? print_circular_bug.isra.38+0x130/0x130
 ? stack_trace_consume_entry+0x90/0x90
 ? save_trace+0x3cc/0x420
 __lock_acquire+0x197e/0x2550
 ? btrfs_inode_clear_file_extent_range+0x9b/0xb0
 ? register_lock_class+0x960/0x960
 lock_acquire+0x103/0x220
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 __mutex_lock+0x13d/0xce0
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 ? __asan_loadN+0xf/0x20
 ? pvclock_clocksource_read+0xeb/0x190
 ? __btrfs_release_delayed_node+0x7c/0x5b0
 ? mutex_lock_io_nested+0xc20/0xc20
 ? __kasan_check_read+0x11/0x20
 ? check_chain_key+0x1e6/0x2e0
 mutex_lock_nested+0x1b/0x20
 ? mutex_lock_nested+0x1b/0x20
 __btrfs_release_delayed_node+0x7c/0x5b0
 btrfs_remove_delayed_node+0x49/0x50
 btrfs_evict_inode+0x6fc/0x900
 ? btrfs_setattr+0x840/0x840
 ? do_raw_spin_unlock+0xa8/0x140
 evict+0x19a/0x2c0
 dispose_list+0xa0/0xe0
 prune_icache_sb+0xbd/0xf0
 ? invalidate_inodes+0x310/0x310
 super_cache_scan+0x1b5/0x250
 do_shrink_slab+0x1f6/0x530
 shrink_slab+0x32e/0x410
 ? do_shrink_slab+0x530/0x530
 ? do_shrink_slab+0x530/0x530
 ? __kasan_check_read+0x11/0x20
 ? mem_cgroup_protected+0x13d/0x260
 shrink_node+0x2a5/0xba0
 balance_pgdat+0x4bd/0x8a0
 ? mem_cgroup_shrink_node+0x490/0x490
 ? _raw_spin_unlock_irq+0x27/0x40
 ? finish_task_switch+0xce/0x390
 ? rcu_read_lock_bh_held+0xb0/0xb0
 kswapd+0x35a/0x800
 ? _raw_spin_unlock_irqrestore+0x4c/0x60
 ? balance_pgdat+0x8a0/0x8a0
 ? finish_wait+0x110/0x110
 ? __kasan_check_read+0x11/0x20
 ? __kthread_parkme+0xc6/0xe0
 ? balance_pgdat+0x8a0/0x8a0
 kthread+0x1e9/0x210
 ? kthread_create_worker_on_cpu+0xc0/0xc0
 ret_from_fork+0x3a/0x50

This is because we hold that delayed node's mutex while doing tree
operations.  Fix this by just wrapping the searches in nofs.

CC: [email protected] # 4.4+
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
RobertCNelson pushed a commit that referenced this pull request Sep 25, 2020
commit 51415b6 upstream.

[BUG]
When balance is canceled, there is a pretty high chance that unmounting
the fs can lead to lead the NULL pointer dereference:

  BTRFS warning (device dm-3): page private not zero on page 223158272
  ...
  BTRFS warning (device dm-3): page private not zero on page 223162368
  BTRFS error (device dm-3): leaked root 18446744073709551608-304 refcount 1
  BUG: kernel NULL pointer dereference, address: 0000000000000168
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 2 PID: 5793 Comm: umount Tainted: G           O      5.7.0-rc5-custom+ #53
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:__lock_acquire+0x5dc/0x24c0
  Call Trace:
   lock_acquire+0xab/0x390
   _raw_spin_lock+0x39/0x80
   btrfs_release_extent_buffer_pages+0xd7/0x200 [btrfs]
   release_extent_buffer+0xb2/0x170 [btrfs]
   free_extent_buffer+0x66/0xb0 [btrfs]
   btrfs_put_root+0x8e/0x130 [btrfs]
   btrfs_check_leaked_roots.cold+0x5/0x5d [btrfs]
   btrfs_free_fs_info+0xe5/0x120 [btrfs]
   btrfs_kill_super+0x1f/0x30 [btrfs]
   deactivate_locked_super+0x3b/0x80
   deactivate_super+0x3e/0x50
   cleanup_mnt+0x109/0x160
   __cleanup_mnt+0x12/0x20
   task_work_run+0x67/0xa0
   exit_to_usermode_loop+0xc5/0xd0
   syscall_return_slowpath+0x205/0x360
   do_syscall_64+0x6e/0xb0
   entry_SYSCALL_64_after_hwframe+0x49/0xb3
  RIP: 0033:0x7fd028ef740b

[CAUSE]
When balance is canceled, all reloc roots are marked as orphan, and
orphan reloc roots are going to be cleaned up.

However for orphan reloc roots and merged reloc roots, their lifespan
are quite different:

	Merged reloc roots	|	Orphan reloc roots by cancel
--------------------------------------------------------------------
create_reloc_root()		| create_reloc_root()
|- refs == 1			| |- refs == 1
				|
btrfs_grab_root(reloc_root);	| btrfs_grab_root(reloc_root);
|- refs == 2			| |- refs == 2
				|
root->reloc_root = reloc_root;	| root->reloc_root = reloc_root;
		>>> No difference so far <<<
				|
prepare_to_merge()		| prepare_to_merge()
|- btrfs_set_root_refs(item, 1);| |- if (!err) (err == -EINTR)
				|
merge_reloc_roots()		| merge_reloc_roots()
|- merge_reloc_root()		| |- Doing nothing to put reloc root
   |- insert_dirty_subvol()	| |- refs == 2
      |- __del_reloc_root()	|
         |- btrfs_put_root()	|
            |- refs == 1	|
		>>> Now orphan reloc roots still have refs 2 <<<
				|
clean_dirty_subvols()		| clean_dirty_subvols()
|- btrfs_drop_snapshot()	| |- btrfS_drop_snapshot()
   |- reloc_root get freed	|    |- reloc_root still has refs 2
				|	related ebs get freed, but
				|	reloc_root still recorded in
				|	allocated_roots
btrfs_check_leaked_roots()	| btrfs_check_leaked_roots()
|- No leaked roots		| |- Leaked reloc_roots detected
				| |- btrfs_put_root()
				|    |- free_extent_buffer(root->node);
				|       |- eb already freed, caused NULL
				|	   pointer dereference

[FIX]
The fix is to clear fs_root->reloc_root and put it at
merge_reloc_roots() time, so that we won't leak reloc roots.

Fixes: d2311e6 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots")
CC: [email protected] # 5.1+
Tested-by: Johannes Thumshirn <[email protected]>
Signed-off-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>
[Manually solve the conflicts due to no btrfs root refs rework]
Signed-off-by: David Sterba <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
RobertCNelson pushed a commit that referenced this pull request Oct 27, 2020
[ Upstream commit c9dfd3f ]

For the duration of mapping eVMCS, it derefences ->memslots without holding
->srcu or ->slots_lock when accessing hv assist page. This patch fixes it by
moving nested_sync_vmcs12_to_shadow to prepare_guest_switch, where the SRCU
is already taken.

It can be reproduced by running kvm's evmcs_test selftest.

  =============================
  warning: suspicious rcu usage
  5.6.0-rc1+ #53 tainted: g        w ioe
  -----------------------------
  ./include/linux/kvm_host.h:623 suspicious rcu_dereference_check() usage!

  other info that might help us debug this:

   rcu_scheduler_active = 2, debug_locks = 1
  1 lock held by evmcs_test/8507:
   #0: ffff9ddd156d00d0 (&vcpu->mutex){+.+.}, at:
kvm_vcpu_ioctl+0x85/0x680 [kvm]

  stack backtrace:
  cpu: 6 pid: 8507 comm: evmcs_test tainted: g        w ioe     5.6.0-rc1+ #53
  hardware name: dell inc. optiplex 7040/0jctf8, bios 1.4.9 09/12/2016
  call trace:
   dump_stack+0x68/0x9b
   kvm_read_guest_cached+0x11d/0x150 [kvm]
   kvm_hv_get_assist_page+0x33/0x40 [kvm]
   nested_enlightened_vmentry+0x2c/0x60 [kvm_intel]
   nested_vmx_handle_enlightened_vmptrld.part.52+0x32/0x1c0 [kvm_intel]
   nested_sync_vmcs12_to_shadow+0x439/0x680 [kvm_intel]
   vmx_vcpu_run+0x67a/0xe60 [kvm_intel]
   vcpu_enter_guest+0x35e/0x1bc0 [kvm]
   kvm_arch_vcpu_ioctl_run+0x40b/0x670 [kvm]
   kvm_vcpu_ioctl+0x370/0x680 [kvm]
   ksys_ioctl+0x235/0x850
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x77/0x780
   entry_syscall_64_after_hwframe+0x49/0xbe

Signed-off-by: Wanpeng Li <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
fhgwright pushed a commit to fhgwright/bb-linux that referenced this pull request Dec 4, 2022
commit 2af89eb upstream.

coresight devices track their connections (output connections) and
hold a reference to the fwnode. When a device goes away, we walk through
the devices on the coresight bus and make sure that the references
are dropped. This happens both ways:
 a) For all output connections from the device, drop the reference to
    the target device via coresight_release_platform_data()

b) Iterate over all the devices on the coresight bus and drop the
   reference to fwnode if *this* device is the target of the output
   connection, via coresight_remove_conns()->coresight_remove_match().

However, the coresight_remove_match() doesn't clear the fwnode field,
after dropping the reference, this causes use-after-free and
additional refcount drops on the fwnode.

e.g., if we have two devices, A and B, with a connection, A -> B.
If we remove B first, B would clear the reference on B, from A
via coresight_remove_match(). But when A is removed, it still has
a connection with fwnode still pointing to B. Thus it tries to  drops
the reference in coresight_release_platform_data(), raising the bells
like :

[   91.990153] ------------[ cut here ]------------
[   91.990163] refcount_t: addition on 0; use-after-free.
[   91.990212] WARNING: CPU: 0 PID: 461 at lib/refcount.c:25 refcount_warn_saturate+0xa0/0x144
[   91.990260] Modules linked in: coresight_funnel coresight_replicator coresight_etm4x(-)
 crct10dif_ce coresight ip_tables x_tables ipv6 [last unloaded: coresight_cpu_debug]
[   91.990398] CPU: 0 PID: 461 Comm: rmmod Tainted: G        W       T 5.19.0-rc2+ beagleboard#53
[   91.990418] Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb  1 2019
[   91.990434] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   91.990454] pc : refcount_warn_saturate+0xa0/0x144
[   91.990476] lr : refcount_warn_saturate+0xa0/0x144
[   91.990496] sp : ffff80000c843640
[   91.990509] x29: ffff80000c843640 x28: ffff800009957c28 x27: ffff80000c8439a8
[   91.990560] x26: ffff00097eff1990 x25: ffff8000092b6ad8 x24: ffff00097eff19a8
[   91.990610] x23: ffff80000c8439a8 x22: 0000000000000000 x21: ffff80000c8439c2
[   91.990659] x20: 0000000000000000 x19: ffff00097eff1a10 x18: ffff80000ab99c40
[   91.990708] x17: 0000000000000000 x16: 0000000000000000 x15: ffff80000abf6fa0
[   91.990756] x14: 000000000000001d x13: 0a2e656572662d72 x12: 657466612d657375
[   91.990805] x11: 203b30206e6f206e x10: 6f69746964646120 x9 : ffff8000081aba28
[   91.990854] x8 : 206e6f206e6f6974 x7 : 69646461203a745f x6 : 746e756f63666572
[   91.990903] x5 : ffff00097648ec58 x4 : 0000000000000000 x3 : 0000000000000027
[   91.990952] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff00080260ba00
[   91.991000] Call trace:
[   91.991012]  refcount_warn_saturate+0xa0/0x144
[   91.991034]  kobject_get+0xac/0xb0
[   91.991055]  of_node_get+0x2c/0x40
[   91.991076]  of_fwnode_get+0x40/0x60
[   91.991094]  fwnode_handle_get+0x3c/0x60
[   91.991116]  fwnode_get_nth_parent+0xf4/0x110
[   91.991137]  fwnode_full_name_string+0x48/0xc0
[   91.991158]  device_node_string+0x41c/0x530
[   91.991178]  pointer+0x320/0x3ec
[   91.991198]  vsnprintf+0x23c/0x750
[   91.991217]  vprintk_store+0x104/0x4b0
[   91.991238]  vprintk_emit+0x8c/0x360
[   91.991257]  vprintk_default+0x44/0x50
[   91.991276]  vprintk+0xcc/0xf0
[   91.991295]  _printk+0x68/0x90
[   91.991315]  of_node_release+0x13c/0x14c
[   91.991334]  kobject_put+0x98/0x114
[   91.991354]  of_node_put+0x24/0x34
[   91.991372]  of_fwnode_put+0x40/0x5c
[   91.991390]  fwnode_handle_put+0x38/0x50
[   91.991411]  coresight_release_platform_data+0x74/0xb0 [coresight]
[   91.991472]  coresight_unregister+0x64/0xcc [coresight]
[   91.991525]  etm4_remove_dev+0x64/0x78 [coresight_etm4x]
[   91.991563]  etm4_remove_amba+0x1c/0x2c [coresight_etm4x]
[   91.991598]  amba_remove+0x3c/0x19c

Reproducible by: (Build all coresight components as modules):

  #!/bin/sh
  while true
  do
     for m in tmc stm cpu_debug etm4x replicator funnel
     do
     	modprobe coresight_${m}
     done

     for m in tmc stm cpu_debug etm4x replicator funnel
     do
     	rmmode coresight_${m}
     done
  done

Cc: [email protected]
Cc: Mathieu Poirier <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Leo Yan <[email protected]>
Signed-off-by: Suzuki K Poulose <[email protected]>
Fixes: 37ea1ff ("coresight: Use fwnode handle instead of device names")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mathieu Poirier <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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2 participants