syzbot

RBP: 0000000000000102 R08: 00007f1c131d7000 R09: 0000000000000000
R10: 0000000000000000 R11: 00007f1c1b5f6550 R12: 0000000000000001
R13: 00007f1c1cc2fc40 R14: 0000000000000000 R15: 00007f1c1b5f65e0
 </TASK>
Huh VM_FAULT_OOM leaked out to the #PF handler. Retrying PF
==================================================================
BUG: KCSAN: data-race in __dentry_kill / shrink_dentry_list

read-write to 0xffff8881071aa840 of 4 bytes by task 21680 on cpu 0:
 d_shrink_del fs/dcache.c:516 [inline]
 shrink_dentry_list+0x1a6/0x3c0 fs/dcache.c:1141
 shrink_dcache_parent+0x42/0x1b0 fs/dcache.c:-1
 d_invalidate+0xa6/0x1c0 fs/dcache.c:1659
 proc_invalidate_siblings_dcache+0x1c0/0x2a0 fs/proc/inode.c:142
 proc_flush_pid+0x1d/0x30 fs/proc/base.c:3485
 release_task+0x992/0xb70 kernel/exit.c:293
 wait_task_zombie kernel/exit.c:1270 [inline]
 wait_consider_task+0x114a/0x1660 kernel/exit.c:1497
 do_wait_thread kernel/exit.c:1560 [inline]
 __do_wait+0xfa/0x510 kernel/exit.c:1678
 do_wait+0xb7/0x250 kernel/exit.c:1712
 kernel_wait4+0x16b/0x1e0 kernel/exit.c:1871
 __do_sys_wait4 kernel/exit.c:1899 [inline]
 __se_sys_wait4 kernel/exit.c:1895 [inline]
 __x64_sys_wait4+0x91/0x120 kernel/exit.c:1895
 x64_sys_call+0x28ec/0x3000 arch/x86/include/generated/asm/syscalls_64.h:62
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881071aa840 of 4 bytes by task 23043 on cpu 1:
 dentry_unlist fs/dcache.c:640 [inline]
 __dentry_kill+0x2aa/0x4b0 fs/dcache.c:684
 dput+0x5e/0xd0 fs/dcache.c:912
 proc_invalidate_siblings_dcache+0x1c8/0x2a0 fs/proc/inode.c:143
 proc_flush_pid+0x1d/0x30 fs/proc/base.c:3485
 release_task+0x992/0xb70 kernel/exit.c:293
 exit_notify kernel/exit.c:779 [inline]
 do_exit+0xd81/0x15c0 kernel/exit.c:979
 do_group_exit+0xff/0x140 kernel/exit.c:1108
 get_signal+0xe58/0xf70 kernel/signal.c:3034
 arch_do_signal_or_restart+0x96/0x440 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x77/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0024040c -> 0x0000000c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 23043 Comm: syz.3.15995 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================