diff options
| -rw-r--r-- | net/bridge/br_multicast.c | 4 | ||||
| -rw-r--r-- | net/core/skbuff.c | 37 | ||||
| -rw-r--r-- | net/ipv4/igmp.c | 33 | ||||
| -rw-r--r-- | net/ipv6/mcast_snoop.c | 33 |
4 files changed, 56 insertions, 51 deletions
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 0b39dcc65b94..1285eaf5dc22 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1591,7 +1591,7 @@ static int br_multicast_ipv4_rcv(struct net_bridge *br, break; } - if (skb_trimmed) + if (skb_trimmed && skb_trimmed != skb) kfree_skb(skb_trimmed); return err; @@ -1636,7 +1636,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, break; } - if (skb_trimmed) + if (skb_trimmed && skb_trimmed != skb) kfree_skb(skb_trimmed); return err; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b6a19ca0f99e..bf9a5d93c2d1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4022,8 +4022,8 @@ EXPORT_SYMBOL(skb_checksum_setup); * Otherwise returns the provided skb. Returns NULL in error cases * (e.g. transport_len exceeds skb length or out-of-memory). * - * Caller needs to set the skb transport header and release the returned skb. - * Provided skb is consumed. + * Caller needs to set the skb transport header and free any returned skb if it + * differs from the provided skb. */ static struct sk_buff *skb_checksum_maybe_trim(struct sk_buff *skb, unsigned int transport_len) @@ -4032,16 +4032,12 @@ static struct sk_buff *skb_checksum_maybe_trim(struct sk_buff *skb, unsigned int len = skb_transport_offset(skb) + transport_len; int ret; - if (skb->len < len) { - kfree_skb(skb); + if (skb->len < len) return NULL; - } else if (skb->len == len) { + else if (skb->len == len) return skb; - } skb_chk = skb_clone(skb, GFP_ATOMIC); - kfree_skb(skb); - if (!skb_chk) return NULL; @@ -4066,8 +4062,8 @@ static struct sk_buff *skb_checksum_maybe_trim(struct sk_buff *skb, * If the skb has data beyond the given transport length, then a * trimmed & cloned skb is checked and returned. * - * Caller needs to set the skb transport header and release the returned skb. - * Provided skb is consumed. + * Caller needs to set the skb transport header and free any returned skb if it + * differs from the provided skb. */ struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, unsigned int transport_len, @@ -4079,23 +4075,26 @@ struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, skb_chk = skb_checksum_maybe_trim(skb, transport_len); if (!skb_chk) - return NULL; + goto err; - if (!pskb_may_pull(skb_chk, offset)) { - kfree_skb(skb_chk); - return NULL; - } + if (!pskb_may_pull(skb_chk, offset)) + goto err; __skb_pull(skb_chk, offset); ret = skb_chkf(skb_chk); __skb_push(skb_chk, offset); - if (ret) { - kfree_skb(skb_chk); - return NULL; - } + if (ret) + goto err; return skb_chk; + +err: + if (skb_chk && skb_chk != skb) + kfree_skb(skb_chk); + + return NULL; + } EXPORT_SYMBOL(skb_checksum_trimmed); diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 651cdf648ec4..9fdfd9deac11 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -1435,33 +1435,35 @@ static int __ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed) struct sk_buff *skb_chk; unsigned int transport_len; unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr); - int ret; + int ret = -EINVAL; transport_len = ntohs(ip_hdr(skb)->tot_len) - ip_hdrlen(skb); - skb_get(skb); skb_chk = skb_checksum_trimmed(skb, transport_len, ip_mc_validate_checksum); if (!skb_chk) - return -EINVAL; + goto err; - if (!pskb_may_pull(skb_chk, len)) { - kfree_skb(skb_chk); - return -EINVAL; - } + if (!pskb_may_pull(skb_chk, len)) + goto err; ret = ip_mc_check_igmp_msg(skb_chk); - if (ret) { - kfree_skb(skb_chk); - return ret; - } + if (ret) + goto err; if (skb_trimmed) *skb_trimmed = skb_chk; - else + /* free now unneeded clone */ + else if (skb_chk != skb) kfree_skb(skb_chk); - return 0; + ret = 0; + +err: + if (ret && skb_chk && skb_chk != skb) + kfree_skb(skb_chk); + + return ret; } /** @@ -1470,7 +1472,7 @@ static int __ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed) * @skb_trimmed: to store an skb pointer trimmed to IPv4 packet tail (optional) * * Checks whether an IPv4 packet is a valid IGMP packet. If so sets - * skb network and transport headers accordingly and returns zero. + * skb transport header accordingly and returns zero. * * -EINVAL: A broken packet was detected, i.e. it violates some internet * standard @@ -1485,7 +1487,8 @@ static int __ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed) * to leave the original skb and its full frame unchanged (which might be * desirable for layer 2 frame jugglers). * - * The caller needs to release a reference count from any returned skb_trimmed. + * Caller needs to set the skb network header and free any returned skb if it + * differs from the provided skb. */ int ip_mc_check_igmp(struct sk_buff *skb, struct sk_buff **skb_trimmed) { diff --git a/net/ipv6/mcast_snoop.c b/net/ipv6/mcast_snoop.c index df8afe5ab31e..9405b04eecc6 100644 --- a/net/ipv6/mcast_snoop.c +++ b/net/ipv6/mcast_snoop.c @@ -143,34 +143,36 @@ static int __ipv6_mc_check_mld(struct sk_buff *skb, struct sk_buff *skb_chk = NULL; unsigned int transport_len; unsigned int len = skb_transport_offset(skb) + sizeof(struct mld_msg); - int ret; + int ret = -EINVAL; transport_len = ntohs(ipv6_hdr(skb)->payload_len); transport_len -= skb_transport_offset(skb) - sizeof(struct ipv6hdr); - skb_get(skb); skb_chk = skb_checksum_trimmed(skb, transport_len, ipv6_mc_validate_checksum); if (!skb_chk) - return -EINVAL; + goto err; - if (!pskb_may_pull(skb_chk, len)) { - kfree_skb(skb_chk); - return -EINVAL; - } + if (!pskb_may_pull(skb_chk, len)) + goto err; ret = ipv6_mc_check_mld_msg(skb_chk); - if (ret) { - kfree_skb(skb_chk); - return ret; - } + if (ret) + goto err; if (skb_trimmed) *skb_trimmed = skb_chk; - else + /* free now unneeded clone */ + else if (skb_chk != skb) kfree_skb(skb_chk); - return 0; + ret = 0; + +err: + if (ret && skb_chk && skb_chk != skb) + kfree_skb(skb_chk); + + return ret; } /** @@ -179,7 +181,7 @@ static int __ipv6_mc_check_mld(struct sk_buff *skb, * @skb_trimmed: to store an skb pointer trimmed to IPv6 packet tail (optional) * * Checks whether an IPv6 packet is a valid MLD packet. If so sets - * skb network and transport headers accordingly and returns zero. + * skb transport header accordingly and returns zero. * * -EINVAL: A broken packet was detected, i.e. it violates some internet * standard @@ -194,7 +196,8 @@ static int __ipv6_mc_check_mld(struct sk_buff *skb, * to leave the original skb and its full frame unchanged (which might be * desirable for layer 2 frame jugglers). * - * The caller needs to release a reference count from any returned skb_trimmed. + * Caller needs to set the skb network header and free any returned skb if it + * differs from the provided skb. */ int ipv6_mc_check_mld(struct sk_buff *skb, struct sk_buff **skb_trimmed) { |