Commit b0380bf6 authored by Pavel Begunkov's avatar Pavel Begunkov
Browse files

io_uring: fix races with file table unregister 



Fixed file table quiesce might unlock ->uring_lock, potentially letting
new requests to be submitted, don't allow those requests to use the
table as they will race with unregistration.

Reported-and-tested-by: default avatarvan fantasy <g1042620637@gmail.com>
Fixes: 05f3fb3c ("io_uring: avoid ring quiesce for fixed file set unregister and update")
Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
parent a7c41b46

fs/io_uring.c

+8 −0
Original line number Diff line number Diff line
@@ -9768,11 +9768,19 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) 


static int io_sqe_files_unregister(struct io_ring_ctx *ctx)

{

	unsigned nr = ctx->nr_user_files;

	int ret;



	if (!ctx->file_data)

		return -ENXIO;



	/*

	 * Quiesce may unlock ->uring_lock, and while it's not held

	 * prevent new requests using the table.

	 */

	ctx->nr_user_files = 0;

	ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);

	ctx->nr_user_files = nr;

	if (!ret)

		__io_sqe_files_unregister(ctx);

	return ret;