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MPTCP packets in tcpdump collected on nexus 4 #349

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ManuAryan opened this issue Jul 31, 2019 · 1 comment
Open

MPTCP packets in tcpdump collected on nexus 4 #349

ManuAryan opened this issue Jul 31, 2019 · 1 comment
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@ManuAryan
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Hi All,

We have collected the tcpdump traffic while downloading the file from http://multipath-tcp.org/snapshots/ after following the procedure to enable MPTCP on nexus 4 device,
we could see the MPTCP packets are going through only the rmnet0 interface (IP : 100.71.52.234)
and able to get syn ack and well successfully, However from the wlan0 interface (IP:10.17.205.190) few MPTCP packets are tried with the same sequence number 0 and didn't receive any syn ack. How to make it send on both the interfaces ? are we missing anything here ?
netcfg shows both the interfaces are up and IPs are shown for the respective interfaces and also amiusingmptcp.de shows mptcp is enabled in the device.

Please refer the screenshot of packet capture here
Screenshot_MPTCP

@matttbe
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matttbe commented Aug 2, 2019

Hi,

However from the wlan0 interface (IP:10.17.205.190) few MPTCP packets are tried with the same sequence number 0 and didn't receive any syn ack.

You will need to understand what happens there. Take traces on the server side to see if these SYN are received. There is maybe a middlebox blocking this between the client and the server on the wireless network (maybe a different path than with amiusingmptcp.de. Or it could come from the firewall of the server.

Anyway from what you explain, the client seems to do what you want but it is after that there is an issue.

matttbe pushed a commit that referenced this issue Jan 25, 2023
commit 991ed014de0840c5dc405b679168924afb2952ac upstream.

We got a issue as fllows:
==================================================================
 kernel BUG at fs/ext4/extents_status.c:203!
 invalid opcode: 0000 [#1] PREEMPT SMP
 CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349
 RIP: 0010:ext4_es_end.isra.0+0x34/0x42
 RSP: 0018:ffffc9000143b768 EFLAGS: 00010203
 RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff
 RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8
 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0
 R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000
 FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  __es_tree_search.isra.0+0x6d/0xf5
  ext4_es_cache_extent+0xfa/0x230
  ext4_cache_extents+0xd2/0x110
  ext4_find_extent+0x5d5/0x8c0
  ext4_ext_map_blocks+0x9c/0x1d30
  ext4_map_blocks+0x431/0xa50
  ext4_mpage_readpages+0x48e/0xe40
  ext4_readahead+0x47/0x50
  read_pages+0x82/0x530
  page_cache_ra_unbounded+0x199/0x2a0
  do_page_cache_ra+0x47/0x70
  page_cache_ra_order+0x242/0x400
  ondemand_readahead+0x1e8/0x4b0
  page_cache_sync_ra+0xf4/0x110
  filemap_get_pages+0x131/0xb20
  filemap_read+0xda/0x4b0
  generic_file_read_iter+0x13a/0x250
  ext4_file_read_iter+0x59/0x1d0
  vfs_read+0x28f/0x460
  ksys_read+0x73/0x160
  __x64_sys_read+0x1e/0x30
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  </TASK>
==================================================================

In the above issue, ioctl invokes the swap_inode_boot_loader function to
swap inode<5> and inode<12>. However, inode<5> contain incorrect imode and
disordered extents, and i_nlink is set to 1. The extents check for inode in
the ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO.
While links_count is set to 1, the extents are not initialized in
swap_inode_boot_loader. After the ioctl command is executed successfully,
the extents are swapped to inode<12>, in this case, run the `cat` command
to view inode<12>. And Bug_ON is triggered due to the incorrect extents.

When the boot loader inode is not initialized, its imode can be one of the
following:
1) the imode is a bad type, which is marked as bad_inode in ext4_iget and
   set to S_IFREG.
2) the imode is good type but not S_IFREG.
3) the imode is S_IFREG.

The BUG_ON may be triggered by bypassing the check in cases 1 and 2.
Therefore, when the boot loader inode is bad_inode or its imode is not
S_IFREG, initialize the inode to avoid triggering the BUG.

Signed-off-by: Baokun Li <[email protected]>
Reviewed-by: Jason Yan <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
matttbe pushed a commit that referenced this issue Jan 25, 2023
commit 991ed014de0840c5dc405b679168924afb2952ac upstream.

We got a issue as fllows:
==================================================================
 kernel BUG at fs/ext4/extents_status.c:203!
 invalid opcode: 0000 [#1] PREEMPT SMP
 CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349
 RIP: 0010:ext4_es_end.isra.0+0x34/0x42
 RSP: 0018:ffffc9000143b768 EFLAGS: 00010203
 RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff
 RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8
 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0
 R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000
 FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  __es_tree_search.isra.0+0x6d/0xf5
  ext4_es_cache_extent+0xfa/0x230
  ext4_cache_extents+0xd2/0x110
  ext4_find_extent+0x5d5/0x8c0
  ext4_ext_map_blocks+0x9c/0x1d30
  ext4_map_blocks+0x431/0xa50
  ext4_mpage_readpages+0x48e/0xe40
  ext4_readahead+0x47/0x50
  read_pages+0x82/0x530
  page_cache_ra_unbounded+0x199/0x2a0
  do_page_cache_ra+0x47/0x70
  page_cache_ra_order+0x242/0x400
  ondemand_readahead+0x1e8/0x4b0
  page_cache_sync_ra+0xf4/0x110
  filemap_get_pages+0x131/0xb20
  filemap_read+0xda/0x4b0
  generic_file_read_iter+0x13a/0x250
  ext4_file_read_iter+0x59/0x1d0
  vfs_read+0x28f/0x460
  ksys_read+0x73/0x160
  __x64_sys_read+0x1e/0x30
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  </TASK>
==================================================================

In the above issue, ioctl invokes the swap_inode_boot_loader function to
swap inode<5> and inode<12>. However, inode<5> contain incorrect imode and
disordered extents, and i_nlink is set to 1. The extents check for inode in
the ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO.
While links_count is set to 1, the extents are not initialized in
swap_inode_boot_loader. After the ioctl command is executed successfully,
the extents are swapped to inode<12>, in this case, run the `cat` command
to view inode<12>. And Bug_ON is triggered due to the incorrect extents.

When the boot loader inode is not initialized, its imode can be one of the
following:
1) the imode is a bad type, which is marked as bad_inode in ext4_iget and
   set to S_IFREG.
2) the imode is good type but not S_IFREG.
3) the imode is S_IFREG.

The BUG_ON may be triggered by bypassing the check in cases 1 and 2.
Therefore, when the boot loader inode is bad_inode or its imode is not
S_IFREG, initialize the inode to avoid triggering the BUG.

Signed-off-by: Baokun Li <[email protected]>
Reviewed-by: Jason Yan <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
matttbe pushed a commit that referenced this issue Jan 25, 2023
commit 991ed014de0840c5dc405b679168924afb2952ac upstream.

We got a issue as fllows:
==================================================================
 kernel BUG at fs/ext4/extents_status.c:203!
 invalid opcode: 0000 [#1] PREEMPT SMP
 CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349
 RIP: 0010:ext4_es_end.isra.0+0x34/0x42
 RSP: 0018:ffffc9000143b768 EFLAGS: 00010203
 RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff
 RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8
 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0
 R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000
 FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  __es_tree_search.isra.0+0x6d/0xf5
  ext4_es_cache_extent+0xfa/0x230
  ext4_cache_extents+0xd2/0x110
  ext4_find_extent+0x5d5/0x8c0
  ext4_ext_map_blocks+0x9c/0x1d30
  ext4_map_blocks+0x431/0xa50
  ext4_mpage_readpages+0x48e/0xe40
  ext4_readahead+0x47/0x50
  read_pages+0x82/0x530
  page_cache_ra_unbounded+0x199/0x2a0
  do_page_cache_ra+0x47/0x70
  page_cache_ra_order+0x242/0x400
  ondemand_readahead+0x1e8/0x4b0
  page_cache_sync_ra+0xf4/0x110
  filemap_get_pages+0x131/0xb20
  filemap_read+0xda/0x4b0
  generic_file_read_iter+0x13a/0x250
  ext4_file_read_iter+0x59/0x1d0
  vfs_read+0x28f/0x460
  ksys_read+0x73/0x160
  __x64_sys_read+0x1e/0x30
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  </TASK>
==================================================================

In the above issue, ioctl invokes the swap_inode_boot_loader function to
swap inode<5> and inode<12>. However, inode<5> contain incorrect imode and
disordered extents, and i_nlink is set to 1. The extents check for inode in
the ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO.
While links_count is set to 1, the extents are not initialized in
swap_inode_boot_loader. After the ioctl command is executed successfully,
the extents are swapped to inode<12>, in this case, run the `cat` command
to view inode<12>. And Bug_ON is triggered due to the incorrect extents.

When the boot loader inode is not initialized, its imode can be one of the
following:
1) the imode is a bad type, which is marked as bad_inode in ext4_iget and
   set to S_IFREG.
2) the imode is good type but not S_IFREG.
3) the imode is S_IFREG.

The BUG_ON may be triggered by bypassing the check in cases 1 and 2.
Therefore, when the boot loader inode is bad_inode or its imode is not
S_IFREG, initialize the inode to avoid triggering the BUG.

Signed-off-by: Baokun Li <[email protected]>
Reviewed-by: Jason Yan <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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