syzbot


KCSAN: data-race in set_nlink / set_nlink

Status: moderation: reported on 2023/12/08 00:02
Subsystems: kernfs
[Documentation on labels]
Reported-by: syzbot+1b6aa3108f79850c5fa6@syzkaller.appspotmail.com
First crash: 782d, last: 23h09m

Sample crash report:
==================================================================
BUG: KCSAN: data-race in set_nlink / set_nlink

read to 0xffff888106448518 of 4 bytes by task 3000 on cpu 0:
 set_nlink+0x2b/0xb0
 kernfs_refresh_inode fs/kernfs/inode.c:180 [inline]
 kernfs_iop_permission+0x1c8/0x210 fs/kernfs/inode.c:288
 do_inode_permission fs/namei.c:525 [inline]
 inode_permission+0x18c/0x300 fs/namei.c:592
 may_lookup fs/namei.c:1821 [inline]
 link_path_walk+0x13e/0x830 fs/namei.c:2427
 path_lookupat+0x72/0x2b0 fs/namei.c:2635
 filename_lookup+0x150/0x340 fs/namei.c:2665
 vfs_statx+0x9a/0x170 fs/stat.c:346
 vfs_fstatat fs/stat.c:368 [inline]
 __do_sys_newfstatat fs/stat.c:532 [inline]
 __se_sys_newfstatat+0xdc/0x300 fs/stat.c:526
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:526
 x64_sys_call+0x236d/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:263
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff888106448518 of 4 bytes by task 7729 on cpu 1:
 set_nlink+0x98/0xb0 fs/inode.c:448
 kernfs_refresh_inode fs/kernfs/inode.c:180 [inline]
 kernfs_iop_permission+0x1c8/0x210 fs/kernfs/inode.c:288
 do_inode_permission fs/namei.c:525 [inline]
 inode_permission+0x18c/0x300 fs/namei.c:592
 may_lookup fs/namei.c:1821 [inline]
 link_path_walk+0x13e/0x830 fs/namei.c:2427
 path_openat+0x1af/0x1fc0 fs/namei.c:3985
 do_filp_open+0x107/0x230 fs/namei.c:4016
 do_sys_openat2+0xab/0x120 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1454
 x64_sys_call+0x2b30/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000009 -> 0x00000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 7729 Comm: udevd Tainted: G        W          6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
==================================================================

Crashes (640):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/11 13:06 upstream febbc555cf0f 43f51a00 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/08 04:15 upstream 7ee983c850b4 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/06 04:35 upstream 92514ef226f5 577d049b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/05 15:41 upstream 5c8c229261f1 4dc70884 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/05 11:45 upstream 5c8c229261f1 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/04 21:54 upstream d009de7d5428 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/04 02:43 upstream 0de63bb7d919 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/02 12:38 upstream a86bf2283d2c 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/02/01 17:01 upstream 60c828cf80c0 aa47157c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/31 17:50 upstream 69e858e0b8b2 aa47157c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/31 11:23 upstream 69e858e0b8b2 4c6ac32f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/30 17:39 upstream 72deda0abee6 4c6ac32f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/30 07:57 upstream ebbb8be421ee afe4eff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/26 17:40 upstream aa22f4da2a46 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/25 22:27 upstream 0f8e26b38d7a 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/25 02:40 upstream 113691ce9f32 1293872d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/24 08:00 upstream bc8198dc7ebc 521b0ce3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/23 17:05 upstream 21266b8df522 a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/22 01:14 upstream b9d8a295ed6b da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/19 05:04 upstream fda5e3f28400 f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/15 20:38 upstream 619f0b6fad52 968edaf4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/14 21:13 upstream c3812b15000c f310a27d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/14 16:24 upstream c45323b7560e f310a27d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/14 05:23 upstream c45323b7560e b1f1cd88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/11 14:42 upstream 77a903cd8e5a 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/11 03:44 upstream 2144da25584e 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/08 03:12 upstream 09a0fa92e5b4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/07 08:06 upstream fbfd64d25c7a f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/06 15:17 upstream 9d89551994a4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/06 00:18 upstream 9244696b34f2 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/05 13:11 upstream ab75170520d4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/04 08:06 upstream 63676eefb7a0 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2025/01/02 18:52 upstream 56e6a3499e14 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/30 18:21 upstream fc033cf25e61 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/29 20:36 upstream 4099a71718b0 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/29 00:59 upstream 059dd502b263 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/28 15:46 upstream fd0584d220fe d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/27 00:53 upstream d6ef8b40d075 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/26 14:01 upstream 9b2ffa6148b1 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/24 18:52 upstream 9b2ffa6148b1 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/24 15:13 upstream f07044dd0df0 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/21 08:00 upstream e9b8ffafd20a d7f584ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/20 04:54 upstream baaa2567a712 5905cb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/19 17:33 upstream eabcdba3ad40 5905cb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/19 03:27 upstream eabcdba3ad40 1432fc84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/18 16:10 upstream aef25be35d23 a0626d3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/17 02:59 upstream f44d154d6e3d eec85da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/16 05:08 upstream 78d4f34e2115 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/15 05:07 upstream a0e3919a2df2 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/12 22:34 upstream 150b567e0d57 530e80f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2024/12/12 12:56 upstream 231825b2e1ff 6f1b0fa8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2023/12/08 00:00 upstream 9ace34a8e446 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
2023/11/23 10:29 upstream 9b6de136b5f0 fc59b78e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in set_nlink / set_nlink
* Struck through repros no longer work on HEAD.