syzbot


KCSAN: data-race in __dentry_kill / __dentry_kill

Status: auto-obsoleted due to no activity on 2024/05/15 11:32
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+3dcfcdecdea7c8055045@syzkaller.appspotmail.com
First crash: 41d, last: 41d

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

write to 0xffff88811b42da80 of 4 bytes by task 3454 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 0xffff88811b42da80 of 4 bytes by task 3449 on cpu 1:
 dentry_unlist fs/dcache.c:573 [inline]
 __dentry_kill+0x2a9/0x4b0 fs/dcache.c:617
 shrink_kill fs/dcache.c:1048 [inline]
 shrink_dentry_list+0x1bc/0x3e0 fs/dcache.c:1075
 shrink_dcache_parent+0x43/0x1b0
 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: 3449 Comm: syz-fuzzer Tainted: G        W          6.9.0-rc3-syzkaller-00023-g2c71fdf02a95 #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
2024/04/10 11:31 upstream 2c71fdf02a95 4320ec32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __dentry_kill / __dentry_kill
* Struck through repros no longer work on HEAD.