From: linke li Date: Fri, 26 Apr 2024 03:24:37 +0000 (+0800) Subject: io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-readi... X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a4d416dc60980f741f0bfa1f34a1059c498c1b4e;p=linux.git io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it In io_msg_exec_remote(), ctx->submitter_task is read using READ_ONCE at the beginning of the function, checked, and then re-read from ctx->submitter_task, voiding all guarantees of the checks. Reuse the value that was read by READ_ONCE to ensure the consistency of the task struct throughout the function. Signed-off-by: linke li Link: https://lore.kernel.org/r/tencent_F9B2296C93928D6F68FF0C95C33475C68209@qq.com Signed-off-by: Jens Axboe --- diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c index cd6dcf634ba3c..d74670b39ed6d 100644 --- a/io_uring/msg_ring.c +++ b/io_uring/msg_ring.c @@ -83,7 +83,7 @@ static int io_msg_exec_remote(struct io_kiocb *req, task_work_func_t func) return -EOWNERDEAD; init_task_work(&msg->tw, func); - if (task_work_add(ctx->submitter_task, &msg->tw, TWA_SIGNAL)) + if (task_work_add(task, &msg->tw, TWA_SIGNAL)) return -EOWNERDEAD; return IOU_ISSUE_SKIP_COMPLETE;