diff options
| author | Konstantin Khlebnikov <koct9i@gmail.com> | 2016-01-08 15:21:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-31 11:23:36 -0800 |
| commit | abefd1b4087b9b5e83e7b4e7689f8b8e3cb2899c (patch) | |
| tree | 317a9c239553d9c22f8cd9108d71bea6adb63431 /net | |
| parent | 4bb526bce19d6e4c8cc862ce304b8c072ef43366 (diff) | |
net: preserve IP control block during GSO segmentation
[ Upstream commit 9207f9d45b0ad071baa128e846d7e7ed85016df3 ]
Skb_gso_segment() uses skb control block during segmentation.
This patch adds 32-bytes room for previous control block which
will be copied into all resulting segments.
This patch fixes kernel crash during fragmenting forwarded packets.
Fragmentation requires valid IP CB in skb for clearing ip options.
Also patch removes custom save/restore in ovs code, now it's redundant.
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Link: http://lkml.kernel.org/r/CALYGNiP-0MZ-FExV2HutTvE9U-QQtkKSoE--KN=JQE5STYsjAA@mail.gmail.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/core/dev.c | 5 | ||||
| -rw-r--r-- | net/ipv4/ip_output.c | 1 | ||||
| -rw-r--r-- | net/openvswitch/datapath.c | 5 | ||||
| -rw-r--r-- | net/xfrm/xfrm_output.c | 2 |
4 files changed, 9 insertions, 4 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index a42b232805a5..185a3398c651 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2479,6 +2479,8 @@ static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path) * * It may return NULL if the skb requires no segmentation. This is * only possible when GSO is used for verifying header integrity. + * + * Segmentation preserves SKB_SGO_CB_OFFSET bytes of previous skb cb. */ struct sk_buff *__skb_gso_segment(struct sk_buff *skb, netdev_features_t features, bool tx_path) @@ -2493,6 +2495,9 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb, return ERR_PTR(err); } + BUILD_BUG_ON(SKB_SGO_CB_OFFSET + + sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb)); + SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb); SKB_GSO_CB(skb)->encap_level = 0; diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index fe16f418e775..51573f8a39bc 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -235,6 +235,7 @@ static int ip_finish_output_gso(struct sock *sk, struct sk_buff *skb) * from host network stack. */ features = netif_skb_features(skb); + BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET); segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); if (IS_ERR_OR_NULL(segs)) { kfree_skb(skb); diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 27e14962b504..b3fe02a2339e 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -337,12 +337,10 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb, unsigned short gso_type = skb_shinfo(skb)->gso_type; struct sw_flow_key later_key; struct sk_buff *segs, *nskb; - struct ovs_skb_cb ovs_cb; int err; - ovs_cb = *OVS_CB(skb); + BUILD_BUG_ON(sizeof(*OVS_CB(skb)) > SKB_SGO_CB_OFFSET); segs = __skb_gso_segment(skb, NETIF_F_SG, false); - *OVS_CB(skb) = ovs_cb; if (IS_ERR(segs)) return PTR_ERR(segs); if (segs == NULL) @@ -360,7 +358,6 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb, /* Queue all of the segments. */ skb = segs; do { - *OVS_CB(skb) = ovs_cb; if (gso_type & SKB_GSO_UDP && skb != segs) key = &later_key; diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c index fbcedbe33190..5097dce5b916 100644 --- a/net/xfrm/xfrm_output.c +++ b/net/xfrm/xfrm_output.c @@ -153,6 +153,8 @@ static int xfrm_output_gso(struct sock *sk, struct sk_buff *skb) { struct sk_buff *segs; + BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET); + BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET); segs = skb_gso_segment(skb, 0); kfree_skb(skb); if (IS_ERR(segs)) |