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authorLinus Lüssing <linus.luessing@c0d3.blue>2016-02-24 04:21:42 +0100
committerDavid S. Miller <davem@davemloft.net>2016-02-25 16:16:38 -0500
commit9b368814b336b0a1a479135eb2815edbc00efd3c (patch)
treecc0a58b8e009c114d0f30a8a024b5c8d78ee9c75 /net/core/skbuff.c
parenta4690afeb0d2d7ba4d60dfa98a89f3bb1ce60ecd (diff)
downloadlinux-9b368814b336b0a1a479135eb2815edbc00efd3c.tar.gz
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/skbuff.c')
-rw-r--r--net/core/skbuff.c22
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;