syzbot


KCSAN: data-race in __dentry_kill / step_into (8)

Status: moderation: reported on 2024/07/01 14:35
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+8cbdf86ac3f842471303@syzkaller.appspotmail.com
First crash: 130d, last: 7d16h
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / step_into (6) fs 1 206d 206d 0/28 auto-obsoleted due to no activity on 2024/05/21 11:40
upstream KCSAN: data-race in __dentry_kill / step_into fs 1 1491d 1491d 0/28 auto-closed as invalid on 2020/11/14 02:21
upstream KCSAN: data-race in __dentry_kill / step_into (5) fs 106 252d 337d 0/28 auto-obsoleted due to no activity on 2024/04/05 18:21
upstream KCSAN: data-race in __dentry_kill / step_into (4) fs 1 986d 986d 0/28 auto-closed as invalid on 2022/04/03 02:19
upstream KCSAN: data-race in __dentry_kill / step_into (7) fs 2 167d 171d 0/28 auto-obsoleted due to no activity on 2024/06/29 19:22
upstream KCSAN: data-race in __dentry_kill / step_into (2) fs 3 1246d 1284d 0/28 auto-closed as invalid on 2021/07/16 10:59
upstream KCSAN: data-race in __dentry_kill / step_into (3) fs 5 1049d 1106d 0/28 auto-closed as invalid on 2022/01/30 10:25

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

read-write to 0xffff8881071ad000 of 4 bytes by task 4169 on cpu 0:
 dentry_unlist fs/dcache.c:560 [inline]
 __dentry_kill+0x22e/0x4c0 fs/dcache.c:629
 dput+0x5c/0xd0 fs/dcache.c:857
 do_unlinkat+0x257/0x4c0 fs/namei.c:4536
 __do_sys_unlink fs/namei.c:4581 [inline]
 __se_sys_unlink fs/namei.c:4579 [inline]
 __x64_sys_unlink+0x2e/0x40 fs/namei.c:4579
 x64_sys_call+0x280f/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:88
 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

read to 0xffff8881071ad000 of 4 bytes by task 3016 on cpu 1:
 __d_entry_type include/linux/dcache.h:404 [inline]
 d_is_symlink include/linux/dcache.h:434 [inline]
 step_into+0x12f/0x810 fs/namei.c:1896
 walk_component+0x169/0x230 fs/namei.c:2059
 lookup_last fs/namei.c:2556 [inline]
 path_lookupat+0x10a/0x2b0 fs/namei.c:2580
 filename_lookup+0x127/0x300 fs/namei.c:2609
 do_readlinkat+0x89/0x210 fs/stat.c:537
 __do_sys_readlink fs/stat.c:574 [inline]
 __se_sys_readlink fs/stat.c:571 [inline]
 __x64_sys_readlink+0x47/0x60 fs/stat.c:571
 x64_sys_call+0x13c3/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:90
 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: 0x00600008 -> 0x00008008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3016 Comm: udevd Not tainted 6.12.0-rc5-syzkaller-00181-g6c52d4da1c74 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/01 17:56 upstream 6c52d4da1c74 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/10/06 01:25 upstream fc20a3e57247 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/09/19 02:43 upstream 4a39ac5b7d62 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/09/12 13:36 upstream 77f587896757 60e1a995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/09/07 07:35 upstream b31c44928842 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/08/24 01:37 upstream 3d5f968a177d d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/08/07 11:26 upstream d4560686726f 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/07/21 03:36 upstream 3c3ff7be9729 b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/07/13 02:12 upstream 528dd46d0fc3 eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/07/08 14:56 upstream 256abd8e550c cde64f7d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2024/07/01 14:35 upstream 22a40d14b572 b294e901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
* Struck through repros no longer work on HEAD.