diff options
authorFlorian Westphal <fw@strlen.de>2016-06-01 02:04:44 +0200
committerSasha Levin <sasha.levin@oracle.com>2016-07-12 08:48:34 -0400
commitbbb7ecc8a2b66fa5422579409dbc18797984c8ea (patch)
parent3b94ada46f61938d9c49aa198fe560b1f8faea79 (diff)
netfilter: x_tables: don't reject valid target size on some architectures
[ Upstream commit 7b7eba0f3515fca3296b8881d583f7c1042f5226 ] Quoting John Stultz: In updating a 32bit arm device from 4.6 to Linus' current HEAD, I noticed I was having some trouble with networking, and realized that /proc/net/ip_tables_names was suddenly empty. Digging through the registration process, it seems we're catching on the: if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 && target_offset + sizeof(struct xt_standard_target) != next_offset) return -EINVAL; Where next_offset seems to be 4 bytes larger then the offset + standard_target struct size. next_offset needs to be aligned via XT_ALIGN (so we can access all members of ip(6)t_entry struct). This problem didn't show up on i686 as it only needs 4-byte alignment for u64, but iptables userspace on other 32bit arches does insert extra padding. Reported-by: John Stultz <john.stultz@linaro.org> Tested-by: John Stultz <john.stultz@linaro.org> Fixes: 7ed2abddd20cf ("netfilter: x_tables: check standard target size too") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
1 files changed, 2 insertions, 2 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 7ec68e8c2302..fe72e632bff4 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -611,7 +611,7 @@ int xt_compat_check_entry_offsets(const void *base, const char *elems,
return -EINVAL;
if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
- target_offset + sizeof(struct compat_xt_standard_target) != next_offset)
+ COMPAT_XT_ALIGN(target_offset + sizeof(struct compat_xt_standard_target)) != next_offset)
return -EINVAL;
/* compat_xt_entry match has less strict aligment requirements,
@@ -693,7 +693,7 @@ int xt_check_entry_offsets(const void *base,
return -EINVAL;
if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0 &&
- target_offset + sizeof(struct xt_standard_target) != next_offset)
+ XT_ALIGN(target_offset + sizeof(struct xt_standard_target)) != next_offset)
return -EINVAL;
return xt_check_entry_match(elems, base + target_offset,