| Message ID | 20190425214650.518-1-shasta@toxcorp.com |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | [net] netfilter: nf_ct_h323: restore boundary check correctness | expand |
On Thu, Apr 25, 2019 at 11:46:50PM +0200, Jakub Jankowski wrote: > Since commit bc7d811ace4a ("netfilter: nf_ct_h323: Convert > CHECK_BOUND macro to function"), NAT traversal for H.323 > doesn't work, failing to parse H323-UserInformation. > nf_h323_error_boundary() compares contents of the bitstring, > not the addresses, preventing valid H.323 packets from being > conntrack'd. > > This looks like an oversight from when CHECK_BOUND macro was > converted to a function. > > To fix it, stop dereferencing bs->cur and bs->end. Applied, thanks.
diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c index 1601275efe2d..4c2ef42e189c 100644 --- a/net/netfilter/nf_conntrack_h323_asn1.c +++ b/net/netfilter/nf_conntrack_h323_asn1.c @@ -172,7 +172,7 @@ static int nf_h323_error_boundary(struct bitstr *bs, size_t bytes, size_t bits) if (bits % BITS_PER_BYTE > 0) bytes++; - if (*bs->cur + bytes > *bs->end) + if (bs->cur + bytes > bs->end) return 1; return 0;
Since commit bc7d811ace4a ("netfilter: nf_ct_h323: Convert CHECK_BOUND macro to function"), NAT traversal for H.323 doesn't work, failing to parse H323-UserInformation. nf_h323_error_boundary() compares contents of the bitstring, not the addresses, preventing valid H.323 packets from being conntrack'd. This looks like an oversight from when CHECK_BOUND macro was converted to a function. To fix it, stop dereferencing bs->cur and bs->end. Fixes: bc7d811ace4a ("netfilter: nf_ct_h323: Convert CHECK_BOUND macro to function") Signed-off-by: Jakub Jankowski <shasta@toxcorp.com> --- net/netfilter/nf_conntrack_h323_asn1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)