[moderation] [block?] KCSAN: data-race in __io_prep_rw / set_task_ioprio

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6832a9317eee Merge tag 'net-6.16-rc7' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=171c7382580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c8b73fe883c5b6ae
dashboard link: https://syzkaller.appspot.com/bug?extid=fd2c9b5e87d20a0dcafb
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
CC: [ax...@kernel.dk 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/1bb7740ffc5f/disk-6832a931.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2dc443e95dff/vmlinux-6832a931.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bdf2866bfebf/bzImage-6832a931.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fd2c9b...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __io_prep_rw / set_task_ioprio

write to 0xffff8881036e3988 of 8 bytes by task 18251 on cpu 1:
set_task_ioprio+0x24f/0x270 block/blk-ioc.c:280
__do_sys_ioprio_set block/ioprio.c:121 [inline]
__se_sys_ioprio_set+0x250/0x5a0 block/ioprio.c:65
__x64_sys_ioprio_set+0x43/0x50 block/ioprio.c:65
x64_sys_call+0x1982/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:252
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 0xffff8881036e3988 of 8 bytes by task 18240 on cpu 0:
__get_task_ioprio include/linux/ioprio.h:59 [inline]
get_current_ioprio include/linux/ioprio.h:83 [inline]
__io_prep_rw+0x210/0x660 io_uring/rw.c:278
io_prep_rw io_uring/rw.c:320 [inline]
io_prep_rwv+0x33/0x230 io_uring/rw.c:342
io_prep_writev+0x22/0x30 io_uring/rw.c:362
io_init_req io_uring/io_uring.c:2139 [inline]
io_submit_sqe io_uring/io_uring.c:2186 [inline]
io_submit_sqes+0x5e5/0xfd0 io_uring/io_uring.c:2337
__do_sys_io_uring_enter io_uring/io_uring.c:3404 [inline]
__se_sys_io_uring_enter+0x1c1/0x1b70 io_uring/io_uring.c:3338
__x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3338
x64_sys_call+0x28c8/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:427
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

value changed: 0x0000000000000000 -> 0xffff8881170bafe0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 18240 Comm: syz.2.5008 Not tainted 6.16.0-rc6-syzkaller-00121-g6832a9317eee #0 PREEMPT(voluntary)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================


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[syzbot]

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