ipv6: accept 64k - 1 packet length in ip6_find_1stfragopt()
authorStefano Brivio <sbrivio@redhat.com>
Fri, 18 Aug 2017 12:40:53 +0000 (14:40 +0200)
committerDavid S. Miller <davem@davemloft.net>
Tue, 22 Aug 2017 17:23:26 +0000 (10:23 -0700)
commit3de33e1ba0506723ab25734e098cf280ecc34756
treeaf00b05e50a42005c9e5a43c0d19964f1e0ae55a
parent6470812e22261d2342ef1597be62e63a0423d691
ipv6: accept 64k - 1 packet length in ip6_find_1stfragopt()

A packet length of exactly IPV6_MAXPLEN is allowed, we should
refuse parsing options only if the size is 64KiB or more.

While at it, remove one extra variable and one assignment which
were also introduced by the commit that introduced the size
check. Checking the sum 'offset + len' and only later adding
'len' to 'offset' doesn't provide any advantage over directly
summing to 'offset' and checking it.

Fixes: 6399f1fae4ec ("ipv6: avoid overflow of offset in ip6_find_1stfragopt")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv6/output_core.c