diff options
| author | Linus Lüssing <linus.luessing@c0d3.blue> | 2016-02-24 04:21:42 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-02-25 16:16:38 -0500 |
| commit | 9b368814b336b0a1a479135eb2815edbc00efd3c (patch) | |
| tree | cc0a58b8e009c114d0f30a8a024b5c8d78ee9c75 /net/core | |
| parent | a4690afeb0d2d7ba4d60dfa98a89f3bb1ce60ecd (diff) | |
| download | lwn-9b368814b336b0a1a479135eb2815edbc00efd3c.tar.gz lwn-9b368814b336b0a1a479135eb2815edbc00efd3c.zip | |
net: fix bridge multicast packet checksum validation
We need to update the skb->csum after pulling the skb, otherwise
an unnecessary checksum (re)computation can ocure for IGMP/MLD packets
in the bridge code. Additionally this fixes the following splats for
network devices / bridge ports with support for and enabled RX checksum
offloading:
[...]
[ 43.986968] eth0: hw csum failure
[ 43.990344] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.4.0 #2
[ 43.996193] Hardware name: BCM2709
[ 43.999647] [<800204e0>] (unwind_backtrace) from [<8001cf14>] (show_stack+0x10/0x14)
[ 44.007432] [<8001cf14>] (show_stack) from [<801ab614>] (dump_stack+0x80/0x90)
[ 44.014695] [<801ab614>] (dump_stack) from [<802e4548>] (__skb_checksum_complete+0x6c/0xac)
[ 44.023090] [<802e4548>] (__skb_checksum_complete) from [<803a055c>] (ipv6_mc_validate_checksum+0x104/0x178)
[ 44.032959] [<803a055c>] (ipv6_mc_validate_checksum) from [<802e111c>] (skb_checksum_trimmed+0x130/0x188)
[ 44.042565] [<802e111c>] (skb_checksum_trimmed) from [<803a06e8>] (ipv6_mc_check_mld+0x118/0x338)
[ 44.051501] [<803a06e8>] (ipv6_mc_check_mld) from [<803b2c98>] (br_multicast_rcv+0x5dc/0xd00)
[ 44.060077] [<803b2c98>] (br_multicast_rcv) from [<803aa510>] (br_handle_frame_finish+0xac/0x51c)
[...]
Fixes: 9afd85c9e455 ("net: Export IGMP/MLD message validation code")
Reported-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/skbuff.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 5bf88f58bee7..8616d1147c93 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2948,6 +2948,24 @@ int skb_append_pagefrags(struct sk_buff *skb, struct page *page, EXPORT_SYMBOL_GPL(skb_append_pagefrags); /** + * skb_push_rcsum - push skb and update receive checksum + * @skb: buffer to update + * @len: length of data pulled + * + * This function performs an skb_push on the packet and updates + * the CHECKSUM_COMPLETE checksum. It should be used on + * receive path processing instead of skb_push unless you know + * that the checksum difference is zero (e.g., a valid IP header) + * or you are setting ip_summed to CHECKSUM_NONE. + */ +static unsigned char *skb_push_rcsum(struct sk_buff *skb, unsigned len) +{ + skb_push(skb, len); + skb_postpush_rcsum(skb, skb->data, len); + return skb->data; +} + +/** * skb_pull_rcsum - pull skb and update receive checksum * @skb: buffer to update * @len: length of data pulled @@ -4084,9 +4102,9 @@ struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb, if (!pskb_may_pull(skb_chk, offset)) goto err; - __skb_pull(skb_chk, offset); + skb_pull_rcsum(skb_chk, offset); ret = skb_chkf(skb_chk); - __skb_push(skb_chk, offset); + skb_push_rcsum(skb_chk, offset); if (ret) goto err; |