| From | Ben Hutchings <> | Date | Wed, 27 Apr 2016 01:02:21 +0200 | Subject | [PATCH 3.16 180/217] netfilter: x_tables: make sure e->next_offset covers remaining blob size |
| |
3.16.35-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Florian Westphal <fw@strlen.de>
commit 6e94e0cfb0887e4013b3b930fa6ab1fe6bb6ba91 upstream.
Otherwise this function may read data beyond the ruleset blob.
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- net/ipv4/netfilter/arp_tables.c | 6 ++++-- net/ipv4/netfilter/ip_tables.c | 6 ++++-- net/ipv6/netfilter/ip6_tables.c | 6 ++++-- 3 files changed, 12 insertions(+), 6 deletions(-)
--- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -563,7 +563,8 @@ static inline int check_entry_size_and_h int err; if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 || - (unsigned char *)e + sizeof(struct arpt_entry) >= limit) { + (unsigned char *)e + sizeof(struct arpt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) { duprintf("Bad offset %p\n", e); return -EINVAL; } @@ -1223,7 +1224,8 @@ check_compat_entry_size_and_hooks(struct duprintf("check_compat_entry_size_and_hooks %p\n", e); if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 || - (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) { + (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) { duprintf("Bad offset %p, limit = %p\n", e, limit); return -EINVAL; } --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -726,7 +726,8 @@ check_entry_size_and_hooks(struct ipt_en int err; if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 || - (unsigned char *)e + sizeof(struct ipt_entry) >= limit) { + (unsigned char *)e + sizeof(struct ipt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) { duprintf("Bad offset %p\n", e); return -EINVAL; } @@ -1489,7 +1490,8 @@ check_compat_entry_size_and_hooks(struct duprintf("check_compat_entry_size_and_hooks %p\n", e); if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 || - (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) { + (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) { duprintf("Bad offset %p, limit = %p\n", e, limit); return -EINVAL; } --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -737,7 +737,8 @@ check_entry_size_and_hooks(struct ip6t_e int err; if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || - (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) { + (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) { duprintf("Bad offset %p\n", e); return -EINVAL; } @@ -1501,7 +1502,8 @@ check_compat_entry_size_and_hooks(struct duprintf("check_compat_entry_size_and_hooks %p\n", e); if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 || - (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit) { + (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit || + (unsigned char *)e + e->next_offset > limit) { duprintf("Bad offset %p, limit = %p\n", e, limit); return -EINVAL; }
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