6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
commit 54559642b96116b45e4b5ca7fd9f7835b8561272 upstream.
There is a report of io_rsrc_ref_quiesce() locking a mutex while not
TASK_RUNNING, which is due to forgetting restoring the state back after
io_run_task_work_sig() and attempts to break out of the waiting loop.
do not call blocking ops when !TASK_RUNNING; state=1 set at
[<ffffffff815d2494>] prepare_to_wait+0xa4/0x380
kernel/sched/wait.c:237
WARNING: CPU: 2 PID: 397056 at kernel/sched/core.c:10099
__might_sleep+0x114/0x160 kernel/sched/core.c:10099
RIP: 0010:__might_sleep+0x114/0x160 kernel/sched/core.c:10099
Call Trace:
<TASK>
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0xb4/0x940 kernel/locking/mutex.c:752
io_rsrc_ref_quiesce+0x590/0x940 io_uring/rsrc.c:253
io_sqe_buffers_unregister+0xa2/0x340 io_uring/rsrc.c:799
__io_uring_register io_uring/register.c:424 [inline]
__do_sys_io_uring_register+0x5b9/0x2400 io_uring/register.c:613
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd8/0x270 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6f/0x77
Reported-by: Li Shi <sl1589472800@xxxxxxxxx>
Fixes: 4ea15b56f0810 ("io_uring/rsrc: use wq for quiescing")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/77966bc104e25b0534995d5dbb152332bc8f31c0.1718196953.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/rsrc.c | 1 +
1 file changed, 1 insertion(+)
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -250,6 +250,7 @@ __cold static int io_rsrc_ref_quiesce(st
ret = io_run_task_work_sig(ctx);
if (ret < 0) {
+ __set_current_state(TASK_RUNNING);
mutex_lock(&ctx->uring_lock);
if (list_empty(&ctx->rsrc_ref_list))
ret = 0;
