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| author | Dave Jones <davej@codemonkey.org.uk> | 2015-05-19 20:55:17 -0400 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2016-07-21 08:35:47 +0200 |
| commit | 02fb0b2c12f38d43aecdd796eb696fae4e515c6d (patch) | |
| tree | 3557ee0b3f1463b0e61bc6b1463511db552b2601 /net/ipv6 | |
| parent | 39d710d9a43073d4937468b7b959f8f86640cca5 (diff) | |
| download | lwn-02fb0b2c12f38d43aecdd796eb696fae4e515c6d.tar.gz lwn-02fb0b2c12f38d43aecdd796eb696fae4e515c6d.zip | |
netfilter: ensure number of counters is >0 in do_replace()
commit 1086bbe97a074844188c6c988fa0b1a98c3ccbb9 upstream.
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>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/netfilter/ip6_tables.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 441a4f823a48..6685d09cdedc 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1256,6 +1256,9 @@ 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); @@ -1790,6 +1793,9 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len) return -ENOMEM; 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); |