The last argument to __skb_header_pointer() should be a buffer large
enough to store struct arphdr. This can be a pointer to a struct arphdr
structure. The code was previously using a pointer to a pointer to
struct arphdr.
By my counting the storage available both before and after is 8 bytes on
x86_64.
Fixes: 55733350e5e8 ("flow disector: ARP support")
Reported-by: Nicolas Iooss <nicolas.iooss_li...@m4x.org>
Signed-off-by: Simon Horman <simon.hor...@netronome.com>
---
Dave,
this problem is present in both net, since v4.11-rc1 and net-next.
However, the code has refactored in net-next. I expect this will result
in a conflict. Let me know if you would like me to post a version for
net-next too.
---
net/core/flow_dissector.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index c35aae13c8d2..d98d4998213d 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -390,7 +390,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
unsigned char ar_tip[4];
} *arp_eth, _arp_eth;
const struct arphdr *arp;
- struct arphdr *_arp;
+ struct arphdr _arp;
arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
hlen, &_arp);
--
2.7.0.rc3.207.g0ac5344
