From: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx> commit e302f1046f4c209291b07ff7bc4d15ca26891f16 upstream. ctx->cq_extra should be protected by completion lock so that the req_need_defer() does the right check. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20211125092103.224502-2-haoxu@xxxxxxxxxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/io_uring.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6544,12 +6544,15 @@ static __cold void io_drain_req(struct i u32 seq = io_get_sequence(req); /* Still need defer if there is pending req in defer list. */ + spin_lock(&ctx->completion_lock); if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) { + spin_unlock(&ctx->completion_lock); queue: ctx->drain_active = false; io_req_task_queue(req); return; } + spin_unlock(&ctx->completion_lock); ret = io_req_prep_async(req); if (ret) {
