From: Pavel Skripkin <paskripkin@xxxxxxxxx>
[ Upstream commit 7c1a80e80cde008f271bae630d28cf684351e807 ]
Syzbot reported memory leak in xfrm_user_rcv_msg(). The
problem was is non-freed skb's frag_list.
In skb_release_all() skb_release_data() will be called only
in case of skb->head != NULL, but netlink_skb_destructor()
sets head to NULL. So, allocated frag_list skb should be
freed manualy, since consume_skb() won't take care of it
Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator")
Reported-and-tested-by: syzbot+fb347cf82c73a90efcca@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/xfrm/xfrm_user.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 45f86a97eaf2..6f97665b632e 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2751,6 +2751,16 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
err = link->doit(skb, nlh, attrs);
+ /* We need to free skb allocated in xfrm_alloc_compat() before
+ * returning from this function, because consume_skb() won't take
+ * care of frag_list since netlink destructor sets
+ * sbk->head to NULL. (see netlink_skb_destructor())
+ */
+ if (skb_has_frag_list(skb)) {
+ kfree_skb(skb_shinfo(skb)->frag_list);
+ skb_shinfo(skb)->frag_list = NULL;
+ }
+
err:
kvfree(nlh64);
return err;
--
2.30.2
