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>
4 files changed