KCSAN: data-race in dput / select_collect (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c2e7554e Merge tag 'gfs2-v5.10-rc4-fixes' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1763e981500000
kernel config: https://syzkaller.appspot.com/x/.config?x=e9a6e9171a00e85a
dashboard link: https://syzkaller.appspot.com/bug?extid=84f4997ac10aa180efcb
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+84f499...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in dput / select_collect

write to 0xffff888133de5780 of 4 bytes by task 8464 on cpu 1:
d_lru_del fs/dcache.c:410 [inline]
select_collect+0xaf/0x2a0 fs/dcache.c:1505
d_walk+0x298/0x4c0 fs/dcache.c:1326
shrink_dcache_parent+0x85/0x3c0 fs/dcache.c:1565
d_invalidate+0x70/0x1b0 fs/dcache.c:1677
proc_invalidate_siblings_dcache+0x1e3/0x2d0 fs/proc/inode.c:150
proc_flush_pid+0x16/0x20 fs/proc/base.c:3323
release_task+0xb01/0xd30 kernel/exit.c:221
wait_task_zombie kernel/exit.c:1091 [inline]
wait_consider_task+0xf89/0x1820 kernel/exit.c:1318
do_wait_thread kernel/exit.c:1381 [inline]
do_wait+0x1b1/0x4a0 kernel/exit.c:1452
kernel_wait4+0x13c/0x1a0 kernel/exit.c:1614
__do_sys_wait4 kernel/exit.c:1642 [inline]
__se_sys_wait4 kernel/exit.c:1638 [inline]
__x64_sys_wait4+0x7a/0x100 kernel/exit.c:1638
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888133de5780 of 4 bytes by task 17080 on cpu 0:
fast_dput fs/dcache.c:746 [inline]
dput+0x2f/0x420 fs/dcache.c:865
proc_invalidate_siblings_dcache+0x1eb/0x2d0 fs/proc/inode.c:151
proc_flush_pid+0x16/0x20 fs/proc/base.c:3323
release_task+0xc1e/0xd30 kernel/exit.c:221
exit_notify kernel/exit.c:684 [inline]
do_exit+0xe4a/0x15a0 kernel/exit.c:829
do_group_exit+0xc8/0x170 kernel/exit.c:906
get_signal+0xf9b/0x1510 kernel/signal.c:2758
arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17080 Comm: syz-executor.2 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.