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* iptables: ensure number of counters is >0 in do_replace()
@ 2015-05-19 23:11 Dave Jones
  2015-05-19 23:19 ` Florian Westphal
  0 siblings, 1 reply; 6+ messages in thread
From: Dave Jones @ 2015-05-19 23:11 UTC (permalink / raw)
  To: netfilter-devel; +Cc: netdev

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.

Signed-off-by: Dave Jones <davej@codemonkey.org.uk>

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index c69db7fa25ee..12a33d178614 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1262,6 +1262,9 @@ do_replace(struct net *net, const void __user *user, unsigned int len)
 	/* overflow check */
 	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
 		return -ENOMEM;
+	if (tmp.num_counters == 0)
+		return -EINVAL;
+
 	tmp.name[sizeof(tmp.name)-1] = 0;
 
 	newinfo = xt_alloc_table_info(tmp.size);

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2015-05-21 11:37 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-05-19 23:11 iptables: ensure number of counters is >0 in do_replace() Dave Jones
2015-05-19 23:19 ` Florian Westphal
2015-05-19 23:42   ` Dave Jones
2015-05-20  0:20     ` David Miller
2015-05-20  0:55       ` netfilter: " Dave Jones
2015-05-21 11:42         ` Pablo Neira Ayuso

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