[PATCH 5.4 41/43] net: add __must_check to skb_put_padto()

Greg Kroah-Hartman
2020-09-25T12:56:23Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 4a009cb04aeca0de60b73f37b102573354214b52 ]

skb_put_padto() and __skb_put_padto() callers
must check return values or risk use-after-free.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/skbuff.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3185,8 +3185,9 @@ static inline int skb_padto(struct sk_bu
* is untouched. Otherwise it is extended. Returns zero on
* success. The skb is freed on error if @free_on_error is true.
*/
-static inline int __skb_put_padto(struct sk_buff *skb, unsigned int len,
- bool free_on_error)
+static inline int __must_check __skb_put_padto(struct sk_buff *skb,
+ unsigned int len,
+ bool free_on_error)
{
unsigned int size = skb->len;

@@ -3209,7 +3210,7 @@ static inline int __skb_put_padto(struct
* is untouched. Otherwise it is extended. Returns zero on
* success. The skb is freed on error.
*/
-static inline int skb_put_padto(struct sk_buff *skb, unsigned int len)
+static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
{
return __skb_put_padto(skb, len, true);
}