[moderation] [fs?] KCSAN: data-race in __dentry_kill / __dentry_kill (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2ccbdf43d5e7 Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10caf256980000
kernel config: https://syzkaller.appspot.com/x/.config?x=68336ea4b6f4fc09
dashboard link: https://syzkaller.appspot.com/bug?extid=fbbed68afcd0efb10bf5
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/26ed33651516/disk-2ccbdf43.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3c0b763ac146/vmlinux-2ccbdf43.xz
kernel image: https://storage.googleapis.com/syzbot-assets/be99b90037ed/bzImage-2ccbdf43.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fbbed6...@syzkaller.appspotmail.com

==================================================================
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
==================================================================


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