From: Stefano Brivio sbrivio@redhat.com
Commit ba5ea614622d ("bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls") replaces direct calls to pskb_may_pull() in br_ipv6_multicast_mld2_report() with calls to ipv6_mc_may_pull(), that returns -EINVAL on buffers too short to be valid IPv6 packets, while maintaining the previous handling of the return code.
This leads to the direct opposite of the intended effect: if the packet is malformed, -EINVAL evaluates as true, and we'll happily proceed with the processing.
Return 0 if the packet is too short, in the same way as this was fixed for IPv4 by commit 083b78a9ed64 ("ip: fix ip_mc_may_pull() return value").
I don't have a reproducer for this, unlike the one referred to by the IPv4 commit, but this is clearly broken.
Fixes: ba5ea614622d ("bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls") Signed-off-by: Stefano Brivio sbrivio@redhat.com Acked-by: Guillaume Nault gnault@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/net/addrconf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -206,7 +206,7 @@ static inline int ipv6_mc_may_pull(struc unsigned int len) { if (skb_transport_offset(skb) + ipv6_transport_len(skb) < len) - return -EINVAL; + return 0;
return pskb_may_pull(skb, len); }