From: Penglei Jiang <superman.xpt@gmail.com>
Date: Tue, 17 Jun 2025 16:56:44 +0000 (-0700)
Subject: io_uring: fix potential page leak in io_sqe_buffer_register()
X-Git-Tag: v6.16-rc3~22^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e1c75831f682eef0f68b35723437146ed86070b1;p=thirdparty%2Flinux.git

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: d8c2237d0aa9 ("io_uring: add io_pin_pages() helper")
Signed-off-by: Penglei Jiang <superman.xpt@gmail.com>
Link: https://lore.kernel.org/r/20250617165644.79165-1-superman.xpt@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 94a9db030e0e5..d724602697e7c 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -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 @@ done:
 	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);
 	}