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authorPavel Begunkov <asml.silence@gmail.com>2023-01-20 19:38:06 +0300
committerJens Axboe <axboe@kernel.dk>2023-01-20 19:49:34 +0300
commit8579538c89e33ce78be2feb41e07489c8cbf8f31 (patch)
treed609c121d5a9eaf5187d772567d1c08c1365928b
parent56d8e3180c065c9b78ed77afcd0cf99677a4e22f (diff)
downloadlinux-8579538c89e33ce78be2feb41e07489c8cbf8f31.tar.xz
io_uring/msg_ring: fix remote queue to disabled ring
IORING_SETUP_R_DISABLED rings don't have the submitter task set, so it's not always safe to use ->submitter_task. Disallow posting msg_ring messaged to disabled rings. Also add task NULL check for loosy sync around testing for IORING_SETUP_R_DISABLED. Cc: stable@vger.kernel.org Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--io_uring/io_uring.c4
-rw-r--r--io_uring/msg_ring.c8
2 files changed, 10 insertions, 2 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 2ac1cd8d23ea..0a4efada9b3c 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3674,7 +3674,7 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
if (ctx->flags & IORING_SETUP_SINGLE_ISSUER
&& !(ctx->flags & IORING_SETUP_R_DISABLED))
- ctx->submitter_task = get_task_struct(current);
+ WRITE_ONCE(ctx->submitter_task, get_task_struct(current));
file = io_uring_get_file(ctx);
if (IS_ERR(file)) {
@@ -3868,7 +3868,7 @@ static int io_register_enable_rings(struct io_ring_ctx *ctx)
return -EBADFD;
if (ctx->flags & IORING_SETUP_SINGLE_ISSUER && !ctx->submitter_task)
- ctx->submitter_task = get_task_struct(current);
+ WRITE_ONCE(ctx->submitter_task, get_task_struct(current));
if (ctx->restrictions.registered)
ctx->restricted = 1;
diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c
index bb868447dcdf..15602a136821 100644
--- a/io_uring/msg_ring.c
+++ b/io_uring/msg_ring.c
@@ -69,6 +69,10 @@ static int io_msg_exec_remote(struct io_kiocb *req, task_work_func_t func)
{
struct io_ring_ctx *ctx = req->file->private_data;
struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
+ struct task_struct *task = READ_ONCE(ctx->submitter_task);
+
+ if (unlikely(!task))
+ return -EOWNERDEAD;
init_task_work(&msg->tw, func);
if (task_work_add(ctx->submitter_task, &msg->tw, TWA_SIGNAL))
@@ -114,6 +118,8 @@ static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags)
if (msg->src_fd || msg->dst_fd || msg->flags)
return -EINVAL;
+ if (target_ctx->flags & IORING_SETUP_R_DISABLED)
+ return -EBADFD;
if (io_msg_need_remote(target_ctx))
return io_msg_exec_remote(req, io_msg_tw_complete);
@@ -206,6 +212,8 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags)
if (target_ctx == ctx)
return -EINVAL;
+ if (target_ctx->flags & IORING_SETUP_R_DISABLED)
+ return -EBADFD;
if (!src_file) {
src_file = io_msg_grab_file(req, issue_flags);
if (!src_file)