diff options
| author | Ross Lagerwall <ross.lagerwall@citrix.com> | 2019-01-17 15:34:38 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-31 08:12:33 +0100 |
| commit | 04663e84f0429d3777ccb2c3f895fc8a37bddf31 (patch) | |
| tree | bc02c4fe9959f7314d9a366ea790bf5d17d10c3d /net | |
| parent | 0ae4bffc96aa1a1dccba04bc39f72cffc5588afc (diff) | |
net: Fix usage of pskb_trim_rcsum
[ Upstream commit 6c57f0458022298e4da1729c67bd33ce41c14e7a ]
In certain cases, pskb_trim_rcsum() may change skb pointers.
Reinitialize header pointers afterwards to avoid potential
use-after-frees. Add a note in the documentation of
pskb_trim_rcsum(). Found by KASAN.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bridge/br_netfilter_ipv6.c | 1 | ||||
| -rw-r--r-- | net/bridge/netfilter/nft_reject_bridge.c | 1 | ||||
| -rw-r--r-- | net/ipv4/ip_input.c | 1 |
3 files changed, 3 insertions, 0 deletions
diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c index 5989661c659f..a1b57cb07f1e 100644 --- a/net/bridge/br_netfilter_ipv6.c +++ b/net/bridge/br_netfilter_ipv6.c @@ -131,6 +131,7 @@ int br_validate_ipv6(struct net *net, struct sk_buff *skb) IPSTATS_MIB_INDISCARDS); goto drop; } + hdr = ipv6_hdr(skb); } if (hdr->nexthdr == NEXTHDR_HOP && br_nf_check_hbh_len(skb)) goto drop; diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c index 4b3df6b0e3b9..d94aaf7c7685 100644 --- a/net/bridge/netfilter/nft_reject_bridge.c +++ b/net/bridge/netfilter/nft_reject_bridge.c @@ -236,6 +236,7 @@ static bool reject6_br_csum_ok(struct sk_buff *skb, int hook) pskb_trim_rcsum(skb, ntohs(ip6h->payload_len) + sizeof(*ip6h))) return false; + ip6h = ipv6_hdr(skb); thoff = ipv6_skip_exthdr(skb, ((u8*)(ip6h+1) - skb->data), &proto, &fo); if (thoff < 0 || thoff >= skb->len || (fo & htons(~0x7)) != 0) return false; diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c index d6feabb03516..bcadca26523b 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -475,6 +475,7 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, goto drop; } + iph = ip_hdr(skb); skb->transport_header = skb->network_header + iph->ihl*4; /* Remove any debris in the socket control block */ |