Messages in this thread Patch in this message | | | From | menglong8.dong@gmail ... | Subject | [PATCH net-next v2 2/4] net: skb: check the boundrary of drop reason in kfree_skb_reason() | Date | Thu, 12 May 2022 20:33:11 +0800 |
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From: Menglong Dong <imagedong@tencent.com>
Sometimes, we may forget to reset skb drop reason to NOT_SPECIFIED after we make it the return value of the functions with return type of enum skb_drop_reason, such as tcp_inbound_md5_hash. Therefore, its value can be SKB_NOT_DROPPED_YET(0), which is invalid for kfree_skb_reason().
So we check the range of drop reason in kfree_skb_reason() and reset it to NOT_SPECIFIED and print a warning with DEBUG_NET_WARN_ON_ONCE() if it is invalid.
Signed-off-by: Menglong Dong <imagedong@tencent.com> --- net/core/skbuff.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 15f7b6f99a8f..e49e43d4c34d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -771,6 +771,11 @@ void kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason) if (!skb_unref(skb)) return; + if (unlikely(reason <= 0 || reason >= SKB_DROP_REASON_MAX)) { + DEBUG_NET_WARN_ON_ONCE(1); + reason = SKB_DROP_REASON_NOT_SPECIFIED; + } + trace_kfree_skb(skb, __builtin_return_address(0), reason); __kfree_skb(skb); } -- 2.36.1
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