syzbot


KCSAN: data-race in __dentry_kill / __dentry_kill (2)

Status: moderation: reported on 2024/06/13 14:41
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+fbbed68afcd0efb10bf5@syzkaller.appspotmail.com
First crash: 29d, last: 29d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __dentry_kill / __dentry_kill fs 1 93d 93d 0/27 auto-obsoleted due to no activity on 2024/05/15 11:32

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

write to 0xffff88811adb83c0 of 4 bytes by task 6884 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
 proc_invalidate_siblings_dcache+0x1e3/0x2b0 fs/proc/inode.c:143
 proc_flush_pid+0x1d/0x30 fs/proc/base.c:3419
 release_task+0xae6/0xc30 kernel/exit.c:281
 wait_task_zombie kernel/exit.c:1185 [inline]
 wait_consider_task+0x116b/0x1670 kernel/exit.c:1412
 do_wait_thread kernel/exit.c:1475 [inline]
 __do_wait+0x100/0x500 kernel/exit.c:1593
 do_wait+0xaf/0x270 kernel/exit.c:1627
 kernel_wait4+0x164/0x1d0 kernel/exit.c:1786
 __do_sys_wait4 kernel/exit.c:1814 [inline]
 __se_sys_wait4 kernel/exit.c:1810 [inline]
 __x64_sys_wait4+0x94/0x120 kernel/exit.c:1810
 x64_sys_call+0x663/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:62
 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 0xffff88811adb83c0 of 4 bytes by task 10728 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
 proc_invalidate_siblings_dcache+0x1e3/0x2b0 fs/proc/inode.c:143
 proc_flush_pid+0x1d/0x30 fs/proc/base.c:3419
 release_task+0xb91/0xc30 kernel/exit.c:281
 exit_notify kernel/exit.c:770 [inline]
 do_exit+0xf5a/0x1710 kernel/exit.c:894
 do_group_exit+0x102/0x150 kernel/exit.c:1023
 get_signal+0xf2f/0x1080 kernel/signal.c:2909
 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+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0028000c -> 0x0000000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10728 Comm: syz-executor.3 Tainted: G        W          6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/13 14:40 upstream 2ccbdf43d5e7 a9616ff5 .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.