| commit | c4c07b4d6fa1f11880eab8e076d3d060ef3f55fc | |
| author | Jann Horn <jannh@google.com> | |
| Wed, 6 Feb 2019 21:56:15 +0000 (6 22:56 +0100) | ||
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | |
| Mon, 11 Feb 2019 16:43:17 +0000 (11 17:43 +0100) | ||
| tree | ba8683c758581ed3dffa2cb5bf58426377cbb179 | treesnapshot (tar.gz zip) |
| parent | 31b58ad0c3279817cd246eab27eaf53b626dfcde | commitdiff |
netfilter: nf_nat_snmp_basic: add missing length checks in ASN.1 cbs
The generic ASN.1 decoder infrastructure doesn't guarantee that callbacks
will get as much data as they expect; callbacks have to check the `datalen`
parameter before looking at `data`. Make sure that snmp_version() and
snmp_helper() don't read/write beyond the end of the packet data.
(Also move the assignment to `pdata` down below the check to make it clear
that it isn't necessarily a pointer we can use before the `datalen` check.)
Fixes: cc2d58634e0f ("netfilter: nf_nat_snmp_basic: use asn1 decoder library")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The generic ASN.1 decoder infrastructure doesn't guarantee that callbacks
will get as much data as they expect; callbacks have to check the `datalen`
parameter before looking at `data`. Make sure that snmp_version() and
snmp_helper() don't read/write beyond the end of the packet data.
(Also move the assignment to `pdata` down below the check to make it clear
that it isn't necessarily a pointer we can use before the `datalen` check.)
Fixes: cc2d58634e0f ("netfilter: nf_nat_snmp_basic: use asn1 decoder library")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| net/ipv4/netfilter/nf_nat_snmp_basic_main.c | diffblobblamehistory |