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authorDave Jones <davej@codemonkey.org.uk>2015-05-19 20:55:17 -0400
committerPablo Neira Ayuso <pablo@netfilter.org>2015-05-20 13:46:49 +0200
commit1086bbe97a074844188c6c988fa0b1a98c3ccbb9 (patch)
treec4b90cdf9b27072391ec62aa06408e1a57baed1e /net/bridge
parent3bfe049807c240344b407e3cfb74544927359817 (diff)
netfilter: ensure number of counters is >0 in do_replace()
After improving setsockopt() coverage in trinity, I started triggering vmalloc failures pretty reliably from this code path: warn_alloc_failed+0xe9/0x140 __vmalloc_node_range+0x1be/0x270 vzalloc+0x4b/0x50 __do_replace+0x52/0x260 [ip_tables] do_ipt_set_ctl+0x15d/0x1d0 [ip_tables] nf_setsockopt+0x65/0x90 ip_setsockopt+0x61/0xa0 raw_setsockopt+0x16/0x60 sock_common_setsockopt+0x14/0x20 SyS_setsockopt+0x71/0xd0 It turns out we don't validate that the num_counters field in the struct we pass in from userspace is initialized. The same problem also exists in ebtables, arptables, ipv6, and the compat variants. Signed-off-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/bridge')
-rw-r--r--net/bridge/netfilter/ebtables.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 91180a7fc943..24c7c96bf5f8 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1117,6 +1117,8 @@ static int do_replace(struct net *net, const void __user *user,
return -ENOMEM;
if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
return -ENOMEM;
+ if (tmp.num_counters == 0)
+ return -EINVAL;
tmp.name[sizeof(tmp.name) - 1] = 0;
@@ -2159,6 +2161,8 @@ static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
return -ENOMEM;
if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
return -ENOMEM;
+ if (tmp.num_counters == 0)
+ return -EINVAL;
memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));

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