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KCSAN: data-race in link_path_walk / shrink_dentry_list (11)

Status: moderation: reported on 2024/06/10 02:37
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+084bdfde57f17b1d4722@syzkaller.appspotmail.com
First crash: 8d10h, last: 8d10h
Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (5) fs 1 827d 827d 0/27 auto-closed as invalid on 2022/04/17 20:20
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (6) fs 1 766d 766d 0/27 auto-closed as invalid on 2022/06/18 02:44
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (8) fs 1 492d 492d 0/27 auto-obsoleted due to no activity on 2023/04/09 05:58
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (4) fs 10 863d 1000d 0/27 auto-closed as invalid on 2022/03/12 22:14
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (2) fs 3 1121d 1156d 0/27 auto-closed as invalid on 2021/06/27 19:17
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (7) fs 1 689d 689d 0/27 auto-closed as invalid on 2022/09/03 00:29
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (3) fs 2 1035d 1039d 0/27 auto-closed as invalid on 2021/09/22 09:34
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (9) fs 1 259d 259d 0/27 auto-obsoleted due to no activity on 2023/11/07 05:43
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list (10) fs 3 168d 190d 0/27 auto-obsoleted due to no activity on 2024/02/06 05:32
upstream KCSAN: data-race in link_path_walk / shrink_dentry_list fs 1 1430d 1430d 0/27 auto-closed as invalid on 2020/08/23 06:27

Sample crash report:
==================================================================
BUG: KCSAN: data-race in link_path_walk / shrink_dentry_list

read-write to 0xffff888108aa6c00 of 4 bytes by task 4069 on cpu 0:
 d_shrink_del fs/dcache.c:449 [inline]
 shrink_dentry_list+0x226/0x3e0 fs/dcache.c:1067
 shrink_dcache_sb+0x154/0x280 fs/dcache.c:1195
 reconfigure_super+0x474/0x5b0 fs/super.c:1050
 do_remount fs/namespace.c:2892 [inline]
 path_mount+0x967/0xb30 fs/namespace.c:3671
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3875
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3875
 x64_sys_call+0x25c9/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:166
 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 0xffff888108aa6c00 of 4 bytes by task 4073 on cpu 1:
 __d_entry_type include/linux/dcache.h:397 [inline]
 d_can_lookup include/linux/dcache.h:412 [inline]
 link_path_walk+0x4c1/0x810 fs/namei.c:2341
 path_parentat fs/namei.c:2540 [inline]
 __filename_parentat+0x13c/0x3c0 fs/namei.c:2564
 filename_parentat fs/namei.c:2582 [inline]
 filename_create+0x77/0x2b0 fs/namei.c:3881
 do_symlinkat+0x84/0x350 fs/namei.c:4508
 __do_sys_symlinkat fs/namei.c:4531 [inline]
 __se_sys_symlinkat fs/namei.c:4528 [inline]
 __x64_sys_symlinkat+0x62/0x70 fs/namei.c:4528
 x64_sys_call+0x1e00/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:267
 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: 0x00280400 -> 0x00200000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4073 Comm: syz-executor.4 Not tainted 6.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/10 02:36 upstream 83a7eefedc9b 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in link_path_walk / shrink_dentry_list
* Struck through repros no longer work on HEAD.