diff options
Diffstat (limited to '0001-ipv6-avoid-overflow-of-offset-in-ip6_find_1stfragopt.patch')
| -rw-r--r-- | 0001-ipv6-avoid-overflow-of-offset-in-ip6_find_1stfragopt.patch | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/0001-ipv6-avoid-overflow-of-offset-in-ip6_find_1stfragopt.patch b/0001-ipv6-avoid-overflow-of-offset-in-ip6_find_1stfragopt.patch new file mode 100644 index 000000000..be8b6c6a0 --- /dev/null +++ b/0001-ipv6-avoid-overflow-of-offset-in-ip6_find_1stfragopt.patch @@ -0,0 +1,54 @@ +From 6399f1fae4ec29fab5ec76070435555e256ca3a6 Mon Sep 17 00:00:00 2001 +From: Sabrina Dubroca <sd@queasysnail.net> +Date: Wed, 19 Jul 2017 22:28:55 +0200 +Subject: [PATCH] ipv6: avoid overflow of offset in ip6_find_1stfragopt + +In some cases, offset can overflow and can cause an infinite loop in +ip6_find_1stfragopt(). Make it unsigned int to prevent the overflow, and +cap it at IPV6_MAXPLEN, since packets larger than that should be invalid. + +This problem has been here since before the beginning of git history. + +Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> +Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + net/ipv6/output_core.c | 8 ++++++-- + 1 file changed, 6 insertions(+), 2 deletions(-) + +diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c +index e9065b8..abb2c30 100644 +--- a/net/ipv6/output_core.c ++++ b/net/ipv6/output_core.c +@@ -78,7 +78,7 @@ EXPORT_SYMBOL(ipv6_select_ident); + + int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) + { +- u16 offset = sizeof(struct ipv6hdr); ++ unsigned int offset = sizeof(struct ipv6hdr); + unsigned int packet_len = skb_tail_pointer(skb) - + skb_network_header(skb); + int found_rhdr = 0; +@@ -86,6 +86,7 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) + + while (offset <= packet_len) { + struct ipv6_opt_hdr *exthdr; ++ unsigned int len; + + switch (**nexthdr) { + +@@ -111,7 +112,10 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) + + exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + + offset); +- offset += ipv6_optlen(exthdr); ++ len = ipv6_optlen(exthdr); ++ if (len + offset >= IPV6_MAXPLEN) ++ return -EINVAL; ++ offset += len; + *nexthdr = &exthdr->nexthdr; + } + +-- +2.9.4 + |