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: 1102d, last: 6h56m

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 (1994):
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
2025/08/09 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
2025/08/01 18:25 upstream f2d282e1dfb3 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/08/01 08:05 upstream f2d282e1dfb3 0c075d67 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/31 18:03 upstream 260f6f4fda93 0c075d67 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/31 02:00 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/30 22:42 upstream 4b290aae788e f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/30 02:59 upstream 0919a5b3b11c f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/29 08:15 upstream ae388edd4a8f c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/28 19:23 upstream 038d61fd6422 6654ea9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/27 23:04 upstream b711733e89a3 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/27 12:32 upstream ec2df4364666 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/26 18:49 upstream 302f88ff3584 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/26 04:29 upstream 5f33ebd2018c fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/25 04:57 upstream 94ce1ac2c9b4 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/24 12:31 upstream 25fae0b93d1d 65d60d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/24 00:15 upstream 01a412d06bc5 0c1d6ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/23 03:43 upstream 89be9a83ccf1 e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/22 18:03 upstream 89be9a83ccf1 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/22 00:14 upstream 89be9a83ccf1 1555463b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/21 14:11 upstream 89be9a83ccf1 56d87229 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/21 03:13 upstream 89be9a83ccf1 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/20 20:24 upstream f4a40a4282f4 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/20 00:15 upstream bf61759db409 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/18 21:09 upstream d786aba32000 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/18 10:09 upstream 6832a9317eee 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/17 18:06 upstream e2291551827f 0d1223f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/17 08:28 upstream e2291551827f 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/16 22:09 upstream 155a3c003e55 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/16 09:09 upstream 155a3c003e55 124ec9cc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dentry_unlink_inode / step_into
2025/07/15 11:01 upstream 155a3c003e55 03fcfc4b .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.