diff options
| author | Eric Dumazet <edumazet@google.com> | 2012-12-06 13:54:59 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-12-07 14:39:29 -0500 |
| commit | c3c7c254b2e8cd99b0adf288c2a1bddacd7ba255 (patch) | |
| tree | cca25bcae0cc6172a616335041c1e54a33db451c | |
| parent | 93b174ad71b08e504c2cf6e8a58ecce778b77a40 (diff) | |
net: gro: fix possible panic in skb_gro_receive()
commit 2e71a6f8084e (net: gro: selective flush of packets) added
a bug for skbs using frag_list. This part of the GRO stack is rarely
used, as it needs skb not using a page fragment for their skb->head.
Most drivers do use a page fragment, but some of them use GFP_KERNEL
allocations for the initial fill of their RX ring buffer.
napi_gro_flush() overwrite skb->prev that was used for these skb to
point to the last skb in frag_list.
Fix this using a separate field in struct napi_gro_cb to point to the
last fragment.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/netdevice.h | 3 | ||||
| -rw-r--r-- | net/core/dev.c | 2 | ||||
| -rw-r--r-- | net/core/skbuff.c | 6 |
3 files changed, 8 insertions, 3 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f8eda0276f03..a848ffc327f4 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1488,6 +1488,9 @@ struct napi_gro_cb { /* Used in ipv6_gro_receive() */ int proto; + + /* used in skb_gro_receive() slow path */ + struct sk_buff *last; }; #define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb) diff --git a/net/core/dev.c b/net/core/dev.c index c0946cb2b354..e5942bf45a6d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3451,6 +3451,8 @@ static int napi_gro_complete(struct sk_buff *skb) struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK]; int err = -ENOENT; + BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb)); + if (NAPI_GRO_CB(skb)->count == 1) { skb_shinfo(skb)->gso_size = 0; goto out; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 4007c1437fda..3f0636cd76cd 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3004,7 +3004,7 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) skb_shinfo(nskb)->gso_size = pinfo->gso_size; pinfo->gso_size = 0; skb_header_release(p); - nskb->prev = p; + NAPI_GRO_CB(nskb)->last = p; nskb->data_len += p->len; nskb->truesize += p->truesize; @@ -3030,8 +3030,8 @@ merge: __skb_pull(skb, offset); - p->prev->next = skb; - p->prev = skb; + NAPI_GRO_CB(p)->last->next = skb; + NAPI_GRO_CB(p)->last = skb; skb_header_release(skb); done: |