syzbot


possible deadlock in path_openat

Status: upstream: reported C repro on 2023/03/13 16:18
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+5065469deff7539fdec3@syzkaller.appspotmail.com
First crash: 345d, last: 9h12m
Bug presence (1)
Date Name Commit Repro Result
2023/06/19 upstream (ToT) 45a3e24f65e9 C [report] possible deadlock in path_openat
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in path_openat fs C done unreliable 349 1420d 1975d 0/26 auto-obsoleted due to no activity on 2022/09/16 21:43
android-49 possible deadlock in path_openat 5 1549d 1565d 0/3 auto-closed as invalid on 2020/03/24 08:43
upstream possible deadlock in path_openat (2) reiserfs C error 305 23d 498d 0/26 upstream: reported C repro on 2022/10/11 06:35
linux-4.14 possible deadlock in path_openat reiserfs C error 327 357d 1765d 0/1 upstream: reported C repro on 2019/04/24 01:40
linux-5.15 possible deadlock in path_openat origin:upstream missing-backport C error 117 39d 341d 0/3 upstream: reported C repro on 2023/03/17 13:15
linux-4.19 possible deadlock in path_openat C error 859 352d 1712d 0/1 upstream: reported C repro on 2019/06/15 07:08
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2024/02/21 17:37 2h47m bisect fix linux-6.1.y job log (0) log
2024/01/11 06:29 1h51m bisect fix linux-6.1.y job log (0) log
2023/12/12 02:42 1h00m bisect fix linux-6.1.y job log (0) log

Sample crash report:
reiserfs: enabling write barrier flush mode
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.1.34-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor235/3539 is trying to acquire lock:
ffff8880747802e0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
ffff8880747802e0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3478 [inline]
ffff8880747802e0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}, at: path_openat+0x7b6/0x2e60 fs/namei.c:3711

but task is already holding lock:
ffff88807ce2e460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (sb_writers#9){.+.+}-{0:0}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1832 [inline]
       sb_start_write+0x4d/0x1c0 include/linux/fs.h:1907
       mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437
       reiserfs_ioctl+0x170/0x340 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&sbi->lock){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
       __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
       reiserfs_write_lock+0x76/0xd0 fs/reiserfs/lock.c:27
       reiserfs_lookup+0x15c/0x4b0 fs/reiserfs/namei.c:364
       __lookup_slow+0x27e/0x3d0 fs/namei.c:1685
       lookup_one_len+0x187/0x2d0 fs/namei.c:2711
       reiserfs_lookup_privroot+0x85/0x1e0 fs/reiserfs/xattr.c:973
       reiserfs_fill_super+0x1957/0x2620 fs/reiserfs/super.c:2192
       mount_bdev+0x2c9/0x3f0 fs/super.c:1423
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
       vfs_get_tree+0x88/0x270 fs/super.c:1553
       do_new_mount+0x28b/0xae0 fs/namespace.c:3040
       do_mount fs/namespace.c:3383 [inline]
       __do_sys_mount fs/namespace.c:3591 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&type->i_mutex_dir_key#6){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:756 [inline]
       open_last_lookups fs/namei.c:3478 [inline]
       path_openat+0x7b6/0x2e60 fs/namei.c:3711
       do_filp_open+0x230/0x480 fs/namei.c:3741
       do_sys_openat2+0x13b/0x500 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  &type->i_mutex_dir_key#6 --> &sbi->lock --> sb_writers#9

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_writers#9);
                               lock(&sbi->lock);
                               lock(sb_writers#9);
  lock(&type->i_mutex_dir_key#6);

 *** DEADLOCK ***

1 lock held by syz-executor235/3539:
 #0: ffff88807ce2e460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393

stack backtrace:
CPU: 0 PID: 3539 Comm: syz-executor235 Not tainted 6.1.34-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3098 [inline]
 check_prevs_add kernel/locking/lockdep.c:3217 [inline]
 validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:756 [inline]
 open_last_lookups fs/namei.c:3478 [inline]
 path_openat+0x7b6/0x2e60 fs/namei.c:3711
 do_filp_open+0x230/0x480 fs/namei.c:3741
 do_sys_openat2+0x13b/0x500 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fe639720909
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffedd79f0d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe639720909
RDX: 000000000000275a RSI: 0000000020000280 RDI: 00000000ffffff9c
RBP: 00007fe6396e01a0 R08: 00000000200000c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe6396e0230
R13: 0000000000000000 R14: 0000000000000000

Crashes (109):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/18 17:20 linux-6.1.y ca87e77a2ef8 f3921d4d .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/09/19 16:44 linux-6.1.y a356197db198 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/09/08 15:38 linux-6.1.y 59b13c2b647e 6654cf89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/11/11 12:32 linux-6.1.y fb2635ac69ab 6d6dbf8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/11/07 00:05 linux-6.1.y 4a61839152cc 78fae24e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/10/16 21:00 linux-6.1.y adc4d740ad9e 342b9c55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/10/15 14:51 linux-6.1.y 082280fe94a0 f757a323 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/09/29 19:51 linux-6.1.y d23900f974e0 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/09/28 17:41 linux-6.1.y d23900f974e0 d265efd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/09/28 08:04 linux-6.1.y d23900f974e0 c2ab1e5d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/09/27 14:55 linux-6.1.y d23900f974e0 2895a507 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/09/13 10:49 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/19 05:49 linux-6.1.y 6c44e13dc284 d216d8a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/07/15 03:56 linux-6.1.y 61fd484b2cf6 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/07/15 00:58 linux-6.1.y 61fd484b2cf6 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/07/14 18:25 linux-6.1.y 61fd484b2cf6 d624500f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/07/11 05:57 linux-6.1.y 61fd484b2cf6 52ae002a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in path_openat
2023/08/29 18:26 linux-6.1.y 024f76bca9d0 ce731e62 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/15 23:45 linux-6.1.y 1321ab403b38 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/14 04:31 linux-6.1.y 1321ab403b38 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/08 22:23 linux-6.1.y 0a4a7855302d 9552ae77 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/08 14:22 linux-6.1.y 52a953d0934b 9552ae77 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/07 11:43 linux-6.1.y 52a953d0934b 0ef3dfda .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/05 16:01 linux-6.1.y 52a953d0934b 4ffcc9ef .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/04 20:13 linux-6.1.y 52a953d0934b cdae481e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/01 21:33 linux-6.1.y d2a6dc4eaf6d df07ffe8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/08/01 18:51 linux-6.1.y d2a6dc4eaf6d df07ffe8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/26 19:27 linux-6.1.y 5302e81aa209 41fe1bae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/26 12:58 linux-6.1.y 5302e81aa209 2a509c27 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/25 19:30 linux-6.1.y 5302e81aa209 6756545c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/24 08:44 linux-6.1.y 75389113731b b03242d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/23 17:53 linux-6.1.y 75389113731b 27cbe77f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/22 12:44 linux-6.1.y a456e1743881 27cbe77f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/22 07:27 linux-6.1.y a456e1743881 27cbe77f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/21 16:55 linux-6.1.y a456e1743881 abdf9bae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/20 00:53 linux-6.1.y a456e1743881 4547cdf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/18 14:09 linux-6.1.y 61fd484b2cf6 022df2bb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/17 16:11 linux-6.1.y 61fd484b2cf6 20f8b3c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/17 13:17 linux-6.1.y 61fd484b2cf6 20f8b3c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/17 03:06 linux-6.1.y 61fd484b2cf6 35d9ecc5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/13 07:21 linux-6.1.y 61fd484b2cf6 86081196 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/13 03:48 linux-6.1.y 61fd484b2cf6 86081196 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/11 11:53 linux-6.1.y 61fd484b2cf6 f8780940 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/11 04:30 linux-6.1.y 61fd484b2cf6 52ae002a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/07 06:43 linux-6.1.y 61fd484b2cf6 22ae5830 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/07 03:54 linux-6.1.y 61fd484b2cf6 22ae5830 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/05 08:15 linux-6.1.y 0f4ac6b4c5f0 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/04 14:52 linux-6.1.y 0f4ac6b4c5f0 f99c2404 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/03 21:33 linux-6.1.y 0f4ac6b4c5f0 6e553898 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/07/01 17:50 linux-6.1.y 0f4ac6b4c5f0 bfc47836 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/06/30 22:44 linux-6.1.y a1c449d00ff8 af3053d2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/06/30 20:55 linux-6.1.y a1c449d00ff8 af3053d2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
2023/03/13 16:18 linux-6.1.y 6449a0ba6843 026e2200 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in path_openat
* Struck through repros no longer work on HEAD.