Messages in this thread Patch in this message | | | From | Kaiyu Zhang <> | Subject | [PATCH] gro: check returned skb of napi_frags_skb() against NULL | Date | Thu, 6 Jul 2023 13:08:00 +0000 |
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Some rogue network adapter and their driver pass bad skbs to GRO. napi_frags_skb() detects this, drops these bad skbs, and return NULL to napi_gro_frags(), which does not check returned skb against NULL and access it. This results in a kernel crash.
A better approach to address these bad skbs would be to issue some warnings and drop them, which napi_frags_skb() already does, and move on without crashing the kernel.
Signed-off-by: Kaiyu Zhang <squirrel.prog@gmail.com> --- net/core/gro.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/core/gro.c b/net/core/gro.c index 0759277dc..18d92016b 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -731,6 +731,9 @@ gro_result_t napi_gro_frags(struct napi_struct *napi) gro_result_t ret; struct sk_buff *skb = napi_frags_skb(napi); + if (unlikely(!skb)) + return GRO_CONSUMED; + trace_napi_gro_frags_entry(skb); ret = napi_frags_finish(napi, skb, dev_gro_receive(napi, skb)); -- 2.34.1
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