syzbot


KCSAN: data-race in __dentry_kill / lookup_fast (10)

Status: auto-obsoleted due to no activity on 2024/05/05 12:07
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+249744a471c6ea990403@syzkaller.appspotmail.com
First crash: 115d, last: 77d
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / lookup_fast (5) fs 12 1112d 1185d 0/27 auto-closed as invalid on 2021/07/05 09:49
upstream KCSAN: data-race in __dentry_kill / lookup_fast (8) fs 8 424d 487d 0/27 auto-obsoleted due to no activity on 2023/05/25 00:07
upstream KCSAN: data-race in __dentry_kill / lookup_fast (2) fs 5 1393d 1453d 0/27 auto-closed as invalid on 2020/09/27 09:27
upstream KCSAN: data-race in __dentry_kill / lookup_fast fs 10 1476d 1569d 0/27 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in __dentry_kill / lookup_fast (7) fs 27 534d 795d 0/27 auto-obsoleted due to no activity on 2023/02/12 11:35
upstream KCSAN: data-race in __dentry_kill / lookup_fast (6) fs 1 940d 940d 0/27 auto-closed as invalid on 2021/12/25 02:52
upstream KCSAN: data-race in __dentry_kill / lookup_fast (4) fs 3 1233d 1258d 0/27 auto-closed as invalid on 2021/03/06 20:57
upstream KCSAN: data-race in __dentry_kill / lookup_fast (3) fs 3 1295d 1287d 0/27 auto-closed as invalid on 2021/01/03 16:37
upstream KCSAN: data-race in __dentry_kill / lookup_fast (9) fs 31 155d 191d 0/27 auto-obsoleted due to no activity on 2024/02/17 10:11

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

read-write to 0xffff88810d2849c0 of 4 bytes by task 8913 on cpu 0:
 dentry_unlist fs/dcache.c:548 [inline]
 __dentry_kill+0x228/0x4b0 fs/dcache.c:617
 dput+0x5c/0xd0 fs/dcache.c:845
 do_unlinkat+0x257/0x4c0 fs/namei.c:4405
 __do_sys_unlink fs/namei.c:4450 [inline]
 __se_sys_unlink fs/namei.c:4448 [inline]
 __x64_sys_unlink+0x30/0x40 fs/namei.c:4448
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff88810d2849c0 of 4 bytes by task 2782 on cpu 1:
 d_revalidate fs/namei.c:860 [inline]
 lookup_fast+0xd9/0x2a0 fs/namei.c:1641
 walk_component+0x3f/0x230 fs/namei.c:2000
 lookup_last fs/namei.c:2461 [inline]
 path_lookupat+0x10a/0x2b0 fs/namei.c:2485
 filename_lookup+0x127/0x300 fs/namei.c:2514
 user_path_at_empty+0x42/0x120 fs/namei.c:2921
 do_readlinkat+0x92/0x210 fs/stat.c:499
 __do_sys_readlink fs/stat.c:532 [inline]
 __se_sys_readlink fs/stat.c:529 [inline]
 __x64_sys_readlink+0x47/0x60 fs/stat.c:529
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

value changed: 0x00600008 -> 0x00008008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2782 Comm: udevd Tainted: G        W          6.9.0-rc1-syzkaller-00355-g712e14250dd2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/31 12:06 upstream 712e14250dd2 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2024/03/10 10:58 upstream 005f6f34bd47 6ee49f2e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
2024/02/22 20:08 upstream 1c892cdd8fe0 8d446f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / lookup_fast
* Struck through repros no longer work on HEAD.