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KCSAN: data-race in d_invalidate / fast_dput (3)

Status: auto-obsoleted due to no activity on 2024/09/21 03:13
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+85f250a0680d314c55d6@syzkaller.appspotmail.com
First crash: 390d, last: 380d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in d_invalidate / fast_dput (4) fs 6 4 295d 335d 0/29 auto-obsoleted due to no activity on 2025/01/05 15:13
upstream KCSAN: data-race in d_invalidate / fast_dput (2) fs 6 1 454d 454d 0/29 auto-obsoleted due to no activity on 2024/07/09 14:03
upstream KCSAN: data-race in d_invalidate / fast_dput (5) fs 6 3 11h01m 52d 0/29 moderation: reported on 2025/07/11 05:11
upstream KCSAN: data-race in d_invalidate / fast_dput fs 6 4 527d 574d 0/29 auto-obsoleted due to no activity on 2024/04/27 15:57

Sample crash report:
==================================================================
BUG: KCSAN: data-race in d_invalidate / fast_dput

write to 0xffff88810699b3d0 of 8 bytes by task 5806 on cpu 0:
 __d_drop fs/dcache.c:516 [inline]
 d_invalidate+0x5c/0x1c0 fs/dcache.c:1592
 __lookup_slow+0x131/0x250 fs/namei.c:1710
 lookup_slow+0x3c/0x60 fs/namei.c:1735
 walk_component fs/namei.c:2039 [inline]
 link_path_walk+0x69e/0x820 fs/namei.c:2404
 path_openat+0x1aa/0x1f10 fs/namei.c:3882
 do_filp_open+0xf7/0x200 fs/namei.c:3913
 do_sys_openat2+0xab/0x120 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1442
 x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258
 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 0xffff88810699b3d0 of 8 bytes by task 6186 on cpu 1:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:354 [inline]
 retain_dentry fs/dcache.c:693 [inline]
 fast_dput+0x65/0x2c0 fs/dcache.c:789
 dput+0x24/0xd0 fs/dcache.c:846
 handle_mounts fs/namei.c:1579 [inline]
 step_into+0x21a/0x810 fs/namei.c:1877
 walk_component fs/namei.c:2045 [inline]
 link_path_walk+0x54c/0x820 fs/namei.c:2404
 path_openat+0x1aa/0x1f10 fs/namei.c:3882
 do_filp_open+0xf7/0x200 fs/namei.c:3913
 do_sys_openat2+0xab/0x120 fs/open.c:1416
 do_sys_open fs/open.c:1431 [inline]
 __do_sys_openat fs/open.c:1447 [inline]
 __se_sys_openat fs/open.c:1442 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1442
 x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258
 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: 0xffff888237b078d0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6186 Comm: udevd Not tainted 6.11.0-rc3-syzkaller-00271-g85652baa895b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/17 03:12 upstream 85652baa895b dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_invalidate / fast_dput
2024/08/06 23:24 upstream eb5e56d14912 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in d_invalidate / fast_dput
* Struck through repros no longer work on HEAD.