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KCSAN: data-race in __dentry_kill / vfs_unlink (5)

Status: auto-closed as invalid on 2022/04/16 18:57
Subsystems: fs
[Documentation on labels]
First crash: 793d, last: 768d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / vfs_unlink (2) fs 2 1016d 1019d 0/26 auto-closed as invalid on 2021/08/12 00:21
upstream KCSAN: data-race in __dentry_kill / vfs_unlink (4) fs 3 868d 899d 0/26 auto-closed as invalid on 2022/01/07 13:09
upstream KCSAN: data-race in __dentry_kill / vfs_unlink fs 1 1184d 1184d 0/26 auto-closed as invalid on 2021/02/25 10:07
upstream KCSAN: data-race in __dentry_kill / vfs_unlink (3) fs 2 950d 958d 0/26 auto-closed as invalid on 2021/10/17 10:47

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

write to 0xffff88811a95dd80 of 4 bytes by task 1810 on cpu 1:
 dont_mount include/linux/dcache.h:348 [inline]
 vfs_unlink+0x2c6/0x580 fs/namei.c:4152
 do_unlinkat+0x278/0x540 fs/namei.c:4218
 __do_sys_unlink fs/namei.c:4266 [inline]
 __se_sys_unlink fs/namei.c:4264 [inline]
 __x64_sys_unlink+0x2c/0x30 fs/namei.c:4264
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88811a95dd80 of 4 bytes by task 1439 on cpu 0:
 dentry_unlist fs/dcache.c:572 [inline]
 __dentry_kill+0x1ef/0x450 fs/dcache.c:603
 dput+0x218/0x430 fs/dcache.c:913
 handle_mounts fs/namei.c:1552 [inline]
 step_into+0x468/0xf70 fs/namei.c:1850
 walk_component+0x1a1/0x360 fs/namei.c:2026
 lookup_last fs/namei.c:2475 [inline]
 path_lookupat+0x12d/0x3d0 fs/namei.c:2499
 filename_lookup+0x130/0x310 fs/namei.c:2528
 user_path_at_empty+0x3e/0x110 fs/namei.c:2851
 do_readlinkat+0x97/0x210 fs/stat.c:443
 __do_sys_readlink fs/stat.c:476 [inline]
 __se_sys_readlink fs/stat.c:473 [inline]
 __x64_sys_readlink+0x43/0x50 fs/stat.c:473
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00600008 -> 0x00000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1439 Comm: udevd Not tainted 5.17.0-rc7-syzkaller-00227-g68453767131a-dirty #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
2022/03/12 18:48 upstream 68453767131a 9e8eaa75 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / vfs_unlink
2022/02/24 13:37 upstream 23d04328444a b28851a4 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / vfs_unlink
2022/02/16 05:51 upstream 705d84a366cf 8b9ca619 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / vfs_unlink
* Struck through repros no longer work on HEAD.