syzbot


KCSAN: data-race in __dentry_kill / d_set_d_op (17)

Status: moderation: reported on 2024/04/18 05:15
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+7dd3b3e7fbec31b5e7cf@syzkaller.appspotmail.com
First crash: 29d, last: 29d
Similar bugs (16)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (9) fs 1 833d 833d 0/26 auto-closed as invalid on 2022/03/12 00:21
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (7) fs 2 1068d 1102d 0/26 auto-closed as invalid on 2021/07/19 11:09
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (3) fs 6 1440d 1481d 0/26 closed as invalid on 2020/06/18 14:24
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (2) fs 9 1570d 1639d 0/26 auto-closed as invalid on 2020/04/08 20:57
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (5) fs 1 1289d 1257d 0/26 auto-closed as invalid on 2020/12/21 11:58
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (10) fs 5 732d 794d 0/26 auto-closed as invalid on 2022/06/20 15:46
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (15) fs 13 241d 301d 0/26 auto-obsoleted due to no activity on 2023/10/24 14:04
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (14) fs 1 337d 337d 0/26 auto-obsoleted due to no activity on 2023/07/21 00:16
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (4) fs 3 1369d 1388d 0/26 auto-closed as invalid on 2020/09/21 06:01
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (11) fs 1 692d 692d 0/26 auto-closed as invalid on 2022/07/30 10:14
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (6) fs 1 1160d 1160d 0/26 auto-closed as invalid on 2021/04/18 21:16
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (16) fs 6 138d 160d 0/26 auto-obsoleted due to no activity on 2024/02/04 06:56
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (12) fs 3 597d 642d 0/26 auto-obsoleted due to no activity on 2022/11/02 16:09
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (8) fs 13 871d 1029d 0/26 auto-closed as invalid on 2022/02/01 06:29
upstream KCSAN: data-race in __dentry_kill / d_set_d_op fs 3 1650d 1657d 0/26 closed as invalid on 2019/11/19 14:14
upstream KCSAN: data-race in __dentry_kill / d_set_d_op (13) fs 4 448d 507d 0/26 auto-obsoleted due to no activity on 2023/04/04 19:35

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

read-write to 0xffff88811981b840 of 4 bytes by task 4533 on cpu 0:
 d_set_d_op+0x15b/0x1f0 fs/dcache.c:1796
 simple_lookup+0x7c/0xa0 fs/libfs.c:79
 lookup_open fs/namei.c:3475 [inline]
 open_last_lookups fs/namei.c:3566 [inline]
 path_openat+0xc85/0x1d80 fs/namei.c:3796
 do_filp_open+0xf7/0x200 fs/namei.c:3826
 do_sys_openat2+0xab/0x120 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1432
 x64_sys_call+0x2cad/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811981b840 of 4 bytes by task 4510 on cpu 1:
 dentry_unlist fs/dcache.c:573 [inline]
 __dentry_kill+0x2a9/0x4b0 fs/dcache.c:617
 dput+0x5c/0xd0 fs/dcache.c:845
 handle_mounts fs/namei.c:1553 [inline]
 step_into+0x21a/0x810 fs/namei.c:1842
 open_last_lookups fs/namei.c:3589 [inline]
 path_openat+0x10fc/0x1d80 fs/namei.c:3796
 do_filp_open+0xf7/0x200 fs/namei.c:3826
 do_sys_openat2+0xab/0x120 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1432
 x64_sys_call+0x2cad/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x10000000 -> 0x00000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4510 Comm: udevd Not tainted 6.9.0-rc4-syzkaller-00034-g4b6b51322118 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/18 05:15 upstream 4b6b51322118 acc528cb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_set_d_op
* Struck through repros no longer work on HEAD.