From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 12 Dec 2024 15:01:52 +0000 (-0700)
Subject: io_uring/rsrc: don't put/free empty buffers
X-Git-Url: https://repo.jachan.dev/J-linux.git/commitdiff_plain/99d6af6e8a22b792e1845b186f943cd10bb4b7b0

io_uring/rsrc: don't put/free empty buffers

If cloning of buffers fail and we have to put the ones already grabbed,
check for NULL buffers and skip those. They used to be dummy ubufs, but
now they are just NULL and that should be checked before reaping them.

Reported-by: chase xd <sl1589472800@gmail.com>
Link: https://lore.kernel.org/io-uring/CADZouDQ7TcKn8gz8_efnyAEp1JvU1ktRk8PWz-tO0FXUoh8VGQ@mail.gmail.com/
Fixes: d50f94d761a5 ("io_uring/rsrc: get rid of the empty node and dummy_ubuf")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index adaae8630932..077f84684c18 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1036,8 +1036,10 @@ static int io_clone_buffers(struct io_ring_ctx *ctx, struct io_ring_ctx *src_ctx
 out_put_free:
 	i = data.nr;
 	while (i--) {
-		io_buffer_unmap(src_ctx, data.nodes[i]);
-		kfree(data.nodes[i]);
+		if (data.nodes[i]) {
+			io_buffer_unmap(src_ctx, data.nodes[i]);
+			kfree(data.nodes[i]);
+		}
 	}
 out_unlock:
 	io_rsrc_data_free(ctx, &data);