Messages in this thread Patch in this message | | | From | kerneljasonxing@gmail ... | Subject | [PATCH net] net: gro: set the last skb->next to NULL when it get merged | Date | Tue, 26 Oct 2021 21:18:59 +0800 |
| |
From: Jason Xing <xingwanli@kuaishou.com>
Setting the @next of the last skb to NULL to prevent the panic in future when someone does something to the last of the gro list but its @next is invalid.
For example, without the fix (commit: ece23711dd95), a panic could happen with the clsact loaded when skb is redirected and then validated in validate_xmit_skb_list() which could access the error addr of the @next of the last skb. Thus, "general protection fault" would appear after that.
Signed-off-by: Jason Xing <xingwanli@kuaishou.com> --- net/core/skbuff.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 2170bea..7b248f1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4396,6 +4396,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb) skb_shinfo(p)->frag_list = skb; else NAPI_GRO_CB(p)->last->next = skb; + skb->next = NULL; NAPI_GRO_CB(p)->last = skb; __skb_header_release(skb); lp = p; -- 1.8.3.1
| |