syzbot


KCSAN: data-race in dentry_unlink_inode / step_into

Status: moderation: reported syz repro on 2023/12/08 00:00
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+10935029822fbc89bbfa@syzkaller.appspotmail.com
First crash: 1120d, last: 1h58m

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

write to 0xffff88810acf5930 of 8 bytes by task 3114 on cpu 1:
 __d_clear_type_and_inode fs/dcache.c:358 [inline]
 dentry_unlink_inode+0x65/0x240 fs/dcache.c:391
 d_delete+0x70/0xa0 fs/dcache.c:2565
 d_delete_notify+0x30/0xe0 include/linux/fsnotify.h:259
 vfs_unlink+0x306/0x3e0 fs/namei.c:4267
 do_unlinkat+0x258/0x510 fs/namei.c:4320
 __do_sys_unlink fs/namei.c:4368 [inline]
 __se_sys_unlink fs/namei.c:4366 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4366
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810acf5930 of 8 bytes by task 2737 on cpu 0:
 step_into+0x115/0x7d0 fs/namei.c:1835
 walk_component+0x164/0x230 fs/namei.c:1999
 lookup_last fs/namei.c:2450 [inline]
 path_lookupat+0x11d/0x2b0 fs/namei.c:2474
 filename_lookup+0x133/0x310 fs/namei.c:2503
 user_path_at_empty+0x3e/0x110 fs/namei.c:2876
 do_readlinkat+0x98/0x210 fs/stat.c:471
 __do_sys_readlink fs/stat.c:504 [inline]
 __se_sys_readlink fs/stat.c:501 [inline]
 __x64_sys_readlink+0x43/0x50 fs/stat.c:501
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffff88810bc26a58 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2737 Comm: udevd Not tainted 6.1.0-syzkaller-13822-g6feb57c2fd7c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================

Crashes (2028):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/21 03:28 upstream 6feb57c2fd7c d3e76707 .config console log report syz [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2022/12/15 08:56 upstream e2ca6ba6ba01 b18f0a64 .config console log report syz [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/28 21:03 upstream 07d9df80082b d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/28 07:16 upstream 07d9df80082b e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/27 19:04 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/26 17:32 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/26 04:59 upstream fab1beda7597 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/26 02:24 upstream b6add54ba618 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/24 19:55 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/23 23:16 upstream 8d245acc1e88 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/23 09:45 upstream 6debb6904172 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/22 19:45 upstream cf6fc5eefc5b bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/22 02:53 upstream 3957a5720157 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/20 22:04 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/20 15:01 upstream b19a97d57c15 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/20 05:29 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/19 23:09 upstream b19a97d57c15 254a27c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/19 02:44 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/18 13:58 upstream c17b750b3ad9 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/18 03:11 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/17 11:53 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/16 20:06 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/16 12:42 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/15 18:26 upstream ee94b00c1a64 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/15 03:09 upstream 24ea63ea3877 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/14 15:07 upstream 0cc53520e68b 5d8c2ac2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/14 10:08 upstream 0cc53520e68b 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/13 22:48 upstream dfc0f6373094 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/13 13:09 upstream 8742b2d8935f 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/13 06:24 upstream 0e39a731820a 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/12 07:44 upstream 53e760d89498 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/11 19:05 upstream 8f5ae30d69d7 c06e8995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/11 00:48 upstream 8f5ae30d69d7 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/10 20:08 upstream 2b38afce25c4 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/09 21:58 upstream 561c80369df0 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/09 08:51 upstream 2988dfed8a5d 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/08 17:39 upstream 37816488247d 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/08 09:35 upstream bec077162bd0 6a893178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/07 11:17 upstream 6e64f4580381 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/06 23:35 upstream cca7a0aae895 9a42d6b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/06 15:59 upstream 479058002c32 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/06 04:20 upstream 6bcdbd62bd56 ffe1dd46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/05 17:55 upstream 7e161a991ea7 37880f40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/05 08:35 upstream 7e161a991ea7 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/04 20:41 upstream d632ab86aff2 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/04 12:56 upstream d2eedaa3909b 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/03 22:17 upstream 352af6a011d5 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/03 04:01 upstream 186f3edfdd41 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/02 14:03 upstream a6923c06a3b2 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/02 02:45 upstream 0905809b38bd 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2023/12/04 23:21 upstream bee0e7762ad2 f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2022/08/03 23:23 upstream ff89dd08c0f0 1c9013ac .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
* Struck through repros no longer work on HEAD.