syzbot


KCSAN: data-race in __dentry_kill / d_walk

Status: moderation: reported on 2024/02/11 13:46
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+54eabfcb4a696e12b7d1@syzkaller.appspotmail.com
First crash: 62d, last: 1d17h

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

write to 0xffff8881069789c0 of 4 bytes by task 4914 on cpu 0:
 d_lru_del fs/dcache.c:437 [inline]
 __dentry_kill+0xa0/0x4b0 fs/dcache.c:598
 dput+0x5c/0xd0 fs/dcache.c:845
 __fput+0x44c/0x660 fs/file_table.c:430
 ____fput+0x15/0x20 fs/file_table.c:450
 task_work_run+0x13a/0x1a0 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x5fd/0x1740 kernel/exit.c:878
 do_group_exit+0x102/0x150 kernel/exit.c:1027
 get_signal+0xf2f/0x1080 kernel/signal.c:2911
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881069789c0 of 4 bytes by task 3077 on cpu 1:
 d_walk+0x278/0x4a0 fs/dcache.c:1250
 shrink_dcache_parent+0xce/0x1b0 fs/dcache.c:1498
 vfs_rmdir+0x28d/0x300 fs/namei.c:4210
 do_rmdir+0x194/0x320 fs/namei.c:4265
 __do_sys_unlinkat fs/namei.c:4441 [inline]
 __se_sys_unlinkat fs/namei.c:4435 [inline]
 __x64_sys_unlinkat+0xa4/0xb0 fs/namei.c:4435
 x64_sys_call+0x767/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:264
 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: 0x00280100 -> 0x00000100

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3077 Comm: syz-fuzzer Not tainted 6.9.0-rc3-syzkaller-00208-g586b5dfb51b9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/12 10:58 upstream 586b5dfb51b9 27de0a5c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/04/01 03:54 upstream 18737353cca0 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/25 02:28 upstream 5e74df2f8f15 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/23 14:39 upstream bfa8f18691ed 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/22 23:04 upstream 8e938e398669 4b6cdce6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/22 07:34 upstream ebc9bee8814d 7a239ce7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/21 12:02 upstream dba89d1b81df 6753db5c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/21 01:29 upstream dba89d1b81df 5b7d42ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/18 12:01 upstream f6cef5f8c37f d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/16 20:34 upstream 66a27abac311 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/03/12 22:48 upstream 855684c7d938 c35c26ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/02/21 09:57 upstream fca7526b7d89 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/02/18 13:09 upstream c02197fc9076 578f7538 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
2024/02/11 13:45 upstream 7521f258ea30 77b23aa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / d_walk
* Struck through repros no longer work on HEAD.