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-rw-r--r--community/quagga/0002-CVE-2012-1820.patch74
1 files changed, 74 insertions, 0 deletions
diff --git a/community/quagga/0002-CVE-2012-1820.patch b/community/quagga/0002-CVE-2012-1820.patch
new file mode 100644
index 000000000..aae2d7b18
--- /dev/null
+++ b/community/quagga/0002-CVE-2012-1820.patch
@@ -0,0 +1,74 @@
+@@ -, +, @@
+ bgpd: CVE-2012-1820, DoS in bgp_capability_orf()
+
+ An ORF (code 3) capability TLV is defined to contain exactly one
+ AFI/SAFI block. Function bgp_capability_orf(), which parses ORF
+ capability TLV, uses do-while cycle to call its helper function
+ bgp_capability_orf_entry(), which actually processes the AFI/SAFI data
+ block. The call is made at least once and repeated as long as the input
+ buffer has enough data for the next call.
+
+ The helper function, bgp_capability_orf_entry(), uses "Number of ORFs"
+ field of the provided AFI/SAFI block to verify, if it fits the input
+ buffer. However, the check is made based on the total length of the ORF
+ TLV regardless of the data already consumed by the previous helper
+ function call(s). This way, the check condition is only valid for the
+ first AFI/SAFI block inside an ORF capability TLV.
+
+ For the subsequent calls of the helper function, if any are made, the
+ check condition may erroneously tell, that the current "Number of ORFs"
+ field fits the buffer boundary, where in fact it does not. This makes it
+ possible to trigger an assertion by feeding an OPEN message with a
+ specially-crafted malformed ORF capability TLV.
+
+ This commit fixes the vulnerability by making the implementation follow
+ the spec.
+--- a/bgpd/bgp_open.c
++++ a/bgpd/bgp_open.c
+@@ -231,7 +231,7 @@ bgp_capability_orf_entry (struct peer *peer, struct capability_header *hdr)
+ }
+
+ /* validate number field */
+- if (sizeof (struct capability_orf_entry) + (entry.num * 2) > hdr->length)
++ if (sizeof (struct capability_orf_entry) + (entry.num * 2) != hdr->length)
+ {
+ zlog_info ("%s ORF Capability entry length error,"
+ " Cap length %u, num %u",
+@@ -335,28 +335,6 @@ bgp_capability_orf_entry (struct peer *peer, struct capability_header *hdr)
+ }
+
+ static int
+-bgp_capability_orf (struct peer *peer, struct capability_header *hdr)
+-{
+- struct stream *s = BGP_INPUT (peer);
+- size_t end = stream_get_getp (s) + hdr->length;
+-
+- assert (stream_get_getp(s) + sizeof(struct capability_orf_entry) <= end);
+-
+- /* We must have at least one ORF entry, as the caller has already done
+- * minimum length validation for the capability code - for ORF there must
+- * at least one ORF entry (header and unknown number of pairs of bytes).
+- */
+- do
+- {
+- if (bgp_capability_orf_entry (peer, hdr) == -1)
+- return -1;
+- }
+- while (stream_get_getp(s) + sizeof(struct capability_orf_entry) < end);
+-
+- return 0;
+-}
+-
+-static int
+ bgp_capability_restart (struct peer *peer, struct capability_header *caphdr)
+ {
+ struct stream *s = BGP_INPUT (peer);
+@@ -573,7 +551,7 @@ bgp_capability_parse (struct peer *peer, size_t length, int *mp_capability,
+ break;
+ case CAPABILITY_CODE_ORF:
+ case CAPABILITY_CODE_ORF_OLD:
+- if (bgp_capability_orf (peer, &caphdr))
++ if (bgp_capability_orf_entry (peer, &caphdr))
+ return -1;
+ break;
+ case CAPABILITY_CODE_RESTART: