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KCSAN: data-race in __dentry_kill / step_into (2)

Status: auto-closed as invalid on 2021/07/16 10:59
Subsystems: fs
[Documentation on labels]
First crash: 1174d, last: 1137d
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 97d 97d 0/27 auto-obsoleted due to no activity on 2024/05/21 11:40
upstream KCSAN: data-race in __dentry_kill / step_into (8) fs 4 1d08h 20d 0/27 moderation: reported on 2024/07/01 14:35
upstream KCSAN: data-race in __dentry_kill / step_into fs 1 1381d 1381d 0/27 auto-closed as invalid on 2020/11/14 02:21
upstream KCSAN: data-race in __dentry_kill / step_into (5) fs 106 142d 227d 0/27 auto-obsoleted due to no activity on 2024/04/05 18:21
upstream KCSAN: data-race in __dentry_kill / step_into (4) fs 1 876d 876d 0/27 auto-closed as invalid on 2022/04/03 02:19
upstream KCSAN: data-race in __dentry_kill / step_into (7) fs 2 57d 61d 0/27 auto-obsoleted due to no activity on 2024/06/29 19:22
upstream KCSAN: data-race in __dentry_kill / step_into (3) fs 5 939d 996d 0/27 auto-closed as invalid on 2022/01/30 10:25

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

write to 0xffff888106bcb540 of 4 bytes by task 807 on cpu 1:
 dentry_unlist fs/dcache.c:522 [inline]
 __dentry_kill+0x147/0x4e0 fs/dcache.c:578
 dentry_kill fs/dcache.c:695 [inline]
 dput+0xc6/0x360 fs/dcache.c:888
 do_unlinkat+0x268/0x4f0 fs/namei.c:4095
 __do_sys_unlink fs/namei.c:4139 [inline]
 __se_sys_unlink fs/namei.c:4137 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4137
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888106bcb540 of 4 bytes by task 1032 on cpu 0:
 __follow_mount_rcu fs/namei.c:1401 [inline]
 handle_mounts fs/namei.c:1458 [inline]
 step_into+0xec/0xec0 fs/namei.c:1772
 walk_component+0x190/0x350 fs/namei.c:1948
 lookup_last fs/namei.c:2397 [inline]
 path_lookupat+0x12d/0x570 fs/namei.c:2421
 filename_lookup+0xff/0x390 fs/namei.c:2454
 user_path_at_empty+0x3b/0x50 fs/namei.c:2734
 do_readlinkat+0x87/0x200 fs/stat.c:425
 __do_sys_readlink fs/stat.c:458 [inline]
 __se_sys_readlink fs/stat.c:455 [inline]
 __x64_sys_readlink+0x43/0x50 fs/stat.c:455
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00600008 -> 0x00008008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1032 Comm: systemd-udevd Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/06/11 10:50 upstream 06af8679449d 1ba81399 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2021/05/12 19:01 upstream dbb5afad100a ed7d41c5 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
2021/05/05 03:09 upstream d665ea6ea86c 06c27ff5 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / step_into
* Struck through repros no longer work on HEAD.