[PATCH AUTOSEL 5.18 52/53] skbuff: don't mix ubuf_info from different sources

Sasha Levin
2022-08-08T01:45:36Z

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit 1b4b2b09d4fb451029b112f17d34792e0277aeb2 ]

We should not append MSG_ZEROCOPY requests to skbuff with non
MSG_ZEROCOPY ubuf_info, they might be not compatible.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/skbuff.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c90c74de90d5..7d35cee8b00e 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1210,6 +1210,10 @@ struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
const u32 byte_limit = 1 << 19; /* limit to a few TSO */
u32 bytelen, next;

+ /* there might be non MSG_ZEROCOPY users */
+ if (uarg->callback != msg_zerocopy_callback)
+ return NULL;
+
/* realloc only when socket is locked (TCP, UDP cork),
* so uarg->len and sk_zckey access is serialized
*/
--
2.35.1