KCSAN: data-race in io_submit_sqes / io_uring_poll (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 09688c0166e7 Linux 5.17-rc8
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=178038b1700000
kernel config: https://syzkaller.appspot.com/x/.config?x=4f2d7d6f883e09d4
dashboard link: https://syzkaller.appspot.com/bug?extid=494e8a731683d8eca84d
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [asml.s...@gmail.com ax...@kernel.dk io-u...@vger.kernel.org linux-...@vger.kernel.org]

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+494e8a...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in io_submit_sqes / io_uring_poll

write to 0xffff88811a8db870 of 4 bytes by task 4252 on cpu 0:
io_get_sqe fs/io_uring.c:7403 [inline]
io_submit_sqes+0x1ec/0x560 fs/io_uring.c:7447
__do_sys_io_uring_enter fs/io_uring.c:10162 [inline]
__se_sys_io_uring_enter+0x212/0xb00 fs/io_uring.c:10104
__x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:10104
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88811a8db870 of 4 bytes by task 4251 on cpu 1:
io_sqring_full fs/io_uring.c:1704 [inline]
io_uring_poll+0x8e/0x146 fs/io_uring.c:9502
vfs_poll include/linux/poll.h:88 [inline]
ep_item_poll fs/eventpoll.c:853 [inline]
ep_send_events fs/eventpoll.c:1692 [inline]
ep_poll fs/eventpoll.c:1806 [inline]
do_epoll_wait+0x6b7/0xf40 fs/eventpoll.c:2234
__do_sys_epoll_wait fs/eventpoll.c:2246 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2241 [inline]
__x64_sys_epoll_wait+0x119/0x140 fs/eventpoll.c:2241
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000357 -> 0x0000036f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4251 Comm: syz-executor.5 Not tainted 5.17.0-rc8-syzkaller-dirty #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.