io_uring/rsrc: don't lock while !TASK_RUNNING

BugLink: https://bugs.launchpad.net/bugs/2074091
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@gmail.com>
Fixes: 4ea15b56f0810 ("io_uring/rsrc: use wq for quiescing")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/77966bc104e25b0534995d5dbb152332bc8f31c0.1718196953.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Portia Stephens <portia.stephens@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 4818b79231ddb0b87271938db32367ff869fdaae..87f9aa7cf9255113274ae064722acf7856915b09 100644 (file)
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -250,6 +250,7 @@ __cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data,
 
                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;