KCSAN: data-race in fuse_dev_do_read / fuse_queue_forget (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b6505459 Linux 5.10-rc6
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11117c45500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c949fed53798f819
dashboard link: https://syzkaller.appspot.com/bug?extid=5f120bcecaadfa7d28f8
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org mik...@szeredi.hu]

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+5f120b...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in fuse_dev_do_read / fuse_queue_forget

write to 0xffff88802f14a6a0 of 8 bytes by task 17550 on cpu 0:
fuse_queue_forget+0x77/0xd0 fs/fuse/dev.c:246
fuse_evict_inode+0x139/0x200 fs/fuse/inode.c:130
evict+0x19f/0x470 fs/inode.c:578
iput_final fs/inode.c:1654 [inline]
iput+0x421/0x510 fs/inode.c:1680
dentry_unlink_inode+0x1f3/0x210 fs/dcache.c:374
__dentry_kill+0x28b/0x450 fs/dcache.c:579
dentry_kill fs/dcache.c:692 [inline]
dput+0x203/0x420 fs/dcache.c:878
__lookup_slow+0x139/0x250 fs/namei.c:1537
lookup_slow fs/namei.c:1561 [inline]
walk_component+0x2a5/0x350 fs/namei.c:1861
lookup_last fs/namei.c:2310 [inline]
path_lookupat+0x11d/0x550 fs/namei.c:2334
do_o_path fs/namei.c:3340 [inline]
path_openat+0x1ae7/0x20a0 fs/namei.c:3362
do_filp_open+0xbd/0x1d0 fs/namei.c:3396
do_sys_openat2+0xa3/0x240 fs/open.c:1168
do_sys_open fs/open.c:1184 [inline]
__do_sys_openat fs/open.c:1200 [inline]
__se_sys_openat fs/open.c:1195 [inline]
__x64_sys_openat+0xef/0x110 fs/open.c:1195
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88802f14a6a0 of 8 bytes by task 17538 on cpu 1:
forget_pending fs/fuse/dev.c:1024 [inline]
request_pending fs/fuse/dev.c:1030 [inline]
fuse_dev_do_read+0x463/0xe70 fs/fuse/dev.c:1235
fuse_dev_read+0xa2/0xe0 fs/fuse/dev.c:1350
call_read_iter include/linux/fs.h:1897 [inline]
new_sync_read fs/read_write.c:415 [inline]
vfs_read+0x552/0x5c0 fs/read_write.c:496
ksys_read+0xce/0x180 fs/read_write.c:634
__do_sys_read fs/read_write.c:644 [inline]
__se_sys_read fs/read_write.c:642 [inline]
__x64_sys_read+0x3e/0x50 fs/read_write.c:642
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17538 Comm: syz-executor.5 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

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