Commit e1c75831 authored by Penglei Jiang's avatar Penglei Jiang Committed by Jens Axboe
Browse files

io_uring: fix potential page leak in io_sqe_buffer_register() 



If allocation of the 'imu' fails, then the existing pages aren't
unpinned in the error path. This is mostly a theoretical issue,
requiring fault injection to hit.

Move unpin_user_pages() to unified error handling to fix the page leak
issue.

Fixes: d8c2237d ("io_uring: add io_pin_pages() helper")
Signed-off-by: default avatarPenglei Jiang <superman.xpt@gmail.com>
Link: https://lore.kernel.org/r/20250617165644.79165-1-superman.xpt@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f2320f1d

io_uring/rsrc.c

+3 −3
Original line number Diff line number Diff line
@@ -809,10 +809,8 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx, 


	imu->nr_bvecs = nr_pages;

	ret = io_buffer_account_pin(ctx, pages, nr_pages, imu, last_hpage);

	if (ret) {

		unpin_user_pages(pages, nr_pages);

	if (ret)

		goto done;

	}



	size = iov->iov_len;

	/* store original address for later verification */
@@ -842,6 +840,8 @@ static struct io_rsrc_node *io_sqe_buffer_register(struct io_ring_ctx *ctx, 
	if (ret) {

		if (imu)

			io_free_imu(ctx, imu);

		if (pages)

			unpin_user_pages(pages, nr_pages);

		io_cache_free(&ctx->node_cache, node);

		node = ERR_PTR(ret);

	}