syzbot


possible deadlock in ocfs2_fiemap

Status: upstream: reported C repro on 2024/09/03 20:43
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+ca440b457d21568f8021@syzkaller.appspotmail.com
First crash: 318d, last: 5h19m
Cause bisection: introduced by (bisect log) :
commit a3c06ae158dd6fa8336157c31d9234689d068d02
Author: Parav Pandit <parav@nvidia.com>
Date: Tue Jan 5 10:32:03 2021 +0000

  vdpa_sim_net: Add support for user supported devices

Crash: possible deadlock in ocfs2_fiemap (log)
Repro: C syz .config
  
Discussions (3)
Title Replies (including bot) Last reply
[PATCH] ocfs2: Fix possible deadlock in ocfs2_fiemap 1 (1) 2024/10/17 08:55
[syzbot] [ocfs2?] possible deadlock in ocfs2_fiemap 0 (5) 2024/10/17 03:19
[syzbot] Monthly ocfs2 report (Sep 2024) 0 (1) 2024/09/23 09:03
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in ocfs2_fiemap 4 21 2d20h 276d 0/3 upstream: reported on 2024/10/11 18:44
linux-5.15 possible deadlock in ocfs2_fiemap 4 17 11d 276d 0/3 upstream: reported on 2024/10/11 15:39
linux-6.6 possible deadlock in ocfs2_fiemap 4 1 9d23h 9d23h 0/2 upstream: reported on 2025/07/05 14:07
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/10/17 03:19 19m lizhi.xu@windriver.com patch upstream OK log
2024/10/17 01:52 13m lizhi.xu@windriver.com patch upstream report log

Sample crash report:
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0 Not tainted
------------------------------------------------------
syz-executor161/5226 is trying to acquire lock:
ffff88807e907398 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0xaa/0x120 mm/memory.c:6700

but task is already holding lock:
ffff8880720d0660 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_fiemap+0x377/0xf80 fs/ocfs2/extent_map.c:755

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&oi->ip_alloc_sem){++++}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       ocfs2_page_mkwrite+0x346/0xed0 fs/ocfs2/mmap.c:142
       do_page_mkwrite+0x198/0x480 mm/memory.c:3162
       do_shared_fault mm/memory.c:5358 [inline]
       do_fault mm/memory.c:5420 [inline]
       do_pte_missing mm/memory.c:3965 [inline]
       handle_pte_fault+0x11fa/0x6800 mm/memory.c:5751
       __handle_mm_fault mm/memory.c:5894 [inline]
       handle_mm_fault+0x1053/0x1ad0 mm/memory.c:6062
       do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #1 (sb_pagefaults){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1716 [inline]
       sb_start_pagefault include/linux/fs.h:1881 [inline]
       ocfs2_page_mkwrite+0x222/0xed0 fs/ocfs2/mmap.c:122
       do_page_mkwrite+0x198/0x480 mm/memory.c:3162
       do_shared_fault mm/memory.c:5358 [inline]
       do_fault mm/memory.c:5420 [inline]
       do_pte_missing mm/memory.c:3965 [inline]
       handle_pte_fault+0x11fa/0x6800 mm/memory.c:5751
       __handle_mm_fault mm/memory.c:5894 [inline]
       handle_mm_fault+0x1053/0x1ad0 mm/memory.c:6062
       do_user_addr_fault arch/x86/mm/fault.c:1389 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x2b9/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __might_fault+0xc6/0x120 mm/memory.c:6700
       _inline_copy_to_user include/linux/uaccess.h:183 [inline]
       _copy_to_user+0x2a/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:216 [inline]
       fiemap_fill_next_extent+0x235/0x410 fs/ioctl.c:145
       ocfs2_fiemap+0x9f1/0xf80 fs/ocfs2/extent_map.c:796
       ioctl_fiemap fs/ioctl.c:220 [inline]
       do_vfs_ioctl+0x1bf8/0x2e40 fs/ioctl.c:841
       __do_sys_ioctl fs/ioctl.c:905 [inline]
       __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &mm->mmap_lock --> sb_pagefaults --> &oi->ip_alloc_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&oi->ip_alloc_sem);
                               lock(sb_pagefaults);
                               lock(&oi->ip_alloc_sem);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

1 lock held by syz-executor161/5226:
 #0: ffff8880720d0660 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_fiemap+0x377/0xf80 fs/ocfs2/extent_map.c:755

stack backtrace:
CPU: 0 UID: 0 PID: 5226 Comm: syz-executor161 Not tainted 6.12.0-rc2-syzkaller-00205-g1d227fcc7222 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __might_fault+0xc6/0x120 mm/memory.c:6700
 _inline_copy_to_user include/linux/uaccess.h:183 [inline]
 _copy_to_user+0x2a/0xb0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:216 [inline]
 fiemap_fill_next_extent+0x235/0x410 fs/ioctl.c:145
 ocfs2_fiemap+0x9f1/0xf80 fs/ocfs2/extent_map.c:796
 ioctl_fiemap fs/ioctl.c:220 [inline]
 do_vfs_ioctl+0x1bf8/0x2e40 fs/ioctl.c:841
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f29e7953939
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc2a87c3b8 EFLAGS

Crashes (1451):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/11 12:41 upstream 1d227fcc7222 cd942402 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2024/09/29 07:51 upstream 3efc57369a0c ba29ff75 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2025/07/15 08:09 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/15 05:24 upstream 155a3c003e55 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/14 21:56 upstream 347e9f5043c8 d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/14 11:24 upstream 347e9f5043c8 d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/14 06:37 upstream 5d5d62298b8b 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/13 09:02 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/13 04:31 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/13 00:00 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/12 18:52 upstream 379f604cc3dc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/12 12:13 upstream 379f604cc3dc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/12 09:55 upstream 379f604cc3dc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/10 19:17 upstream bc9ff192a6c9 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/10 18:06 upstream 8c2e52ebbe88 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/10 05:32 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/10 02:44 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/09 22:44 upstream 8c2e52ebbe88 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/09 19:13 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/09 17:52 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/09 15:49 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/09 08:30 upstream 733923397fd9 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/09 06:44 upstream 733923397fd9 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/09 00:37 upstream d006330be3f7 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/08 17:23 upstream d7b8f8e20813 abade794 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/08 09:13 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/08 06:10 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/07 19:03 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/07 13:11 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/07 05:53 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/06 20:18 upstream 1f988d0788f5 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/06 15:54 upstream 1f988d0788f5 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/06 02:26 upstream 05df91921da6 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ocfs2_fiemap
2025/07/05 23:52 upstream 05df91921da6 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/05 08:55 upstream a79a588fc176 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/05 05:41 upstream 4c06e63b9203 d869b261 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/05/19 12:27 upstream a5806cd506af f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in ocfs2_fiemap
2025/07/15 00:48 upstream 347e9f5043c8 03fcfc4b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2025/07/12 04:33 upstream 40f92e79b0aa 3cda49cf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2025/07/11 13:51 upstream bc9ff192a6c9 3cda49cf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2025/07/11 07:54 upstream bc9ff192a6c9 3cda49cf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2025/07/11 07:54 upstream bc9ff192a6c9 3cda49cf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2024/09/01 08:09 upstream 6cd90e5ea72f 1eda0d14 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2024/08/30 20:38 upstream 20371ba12063 db150e23 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root possible deadlock in ocfs2_fiemap
2025/07/13 18:26 linux-next a62b7a37e6fc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/11 11:36 linux-next a62b7a37e6fc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/11 02:21 linux-next b551c4e2a98a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/10 23:57 linux-next b551c4e2a98a 19d4829f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/07 09:24 linux-next 26ffb3d6f02c 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/05 07:19 linux-next 26ffb3d6f02c 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/04 18:45 linux-next 26ffb3d6f02c d869b261 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ocfs2_fiemap
2025/07/15 03:58 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ec4801305969 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in ocfs2_fiemap
2025/07/14 18:53 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ec4801305969 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in ocfs2_fiemap
2025/07/13 01:54 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ec4801305969 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in ocfs2_fiemap
2025/07/12 22:07 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ec4801305969 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in ocfs2_fiemap
2025/07/05 11:49 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 7482bb149b9f 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in ocfs2_fiemap
* Struck through repros no longer work on HEAD.