From 44c8962f48a67fbe0fbc8fd830d2f51ae15541a4 Mon Sep 17 00:00:00 2001 From: Abhishek Bachiphale Date: Mon, 18 May 2026 22:43:36 +0530 Subject: [PATCH] dnsmasq: fix CVE-2026-5172 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A buffer overflow in dnsmasq’s extract_addresses() function allows an attacker to trigger a heap out-of-bounds read and crash by exploiting a malformed DNS response, enabling extract_name() to advance the pointer past the record’s end. Reference: [ https://nvd.nist.gov/vuln/detail/CVE-2026-5172 ] Signed-off-by: Abhishek Bachiphale Signed-off-by: Khem Raj --- .../recipes-support/dnsmasq/dnsmasq_2.92.bb | 1 + .../dnsmasq/files/CVE-2026-5172.patch | 34 +++++++++++++++++++ 2 files changed, 35 insertions(+) create mode 100644 meta-networking/recipes-support/dnsmasq/files/CVE-2026-5172.patch diff --git a/meta-networking/recipes-support/dnsmasq/dnsmasq_2.92.bb b/meta-networking/recipes-support/dnsmasq/dnsmasq_2.92.bb index 4ae650f7e7..c19467aed9 100644 --- a/meta-networking/recipes-support/dnsmasq/dnsmasq_2.92.bb +++ b/meta-networking/recipes-support/dnsmasq/dnsmasq_2.92.bb @@ -20,6 +20,7 @@ SRC_URI = "http://www.thekelleys.org.uk/dnsmasq/${@['archive/', ''][float(d.getV file://CVE-2026-4891.patch \ file://CVE-2026-4892.patch \ file://CVE-2026-4893.patch \ + file://CVE-2026-5172.patch \ " SRC_URI[sha256sum] = "fd908e79ff37f73234afcb6d3363f78353e768703d92abd8e3220ade6819b1e1" diff --git a/meta-networking/recipes-support/dnsmasq/files/CVE-2026-5172.patch b/meta-networking/recipes-support/dnsmasq/files/CVE-2026-5172.patch new file mode 100644 index 0000000000..ce6e0f464b --- /dev/null +++ b/meta-networking/recipes-support/dnsmasq/files/CVE-2026-5172.patch @@ -0,0 +1,34 @@ +commit fa3c8ddef6712b52f562813317e6a997e1210123 +Author: Simon Kelley +Date: Mon Mar 30 16:24:33 2026 +0100 + +Fix buffer overflow vulnerability in extract_addresses() CVE-2026-5172 + +Thanks to Hugo Martinez Ray for spotting this. + +The value of rdlen for an RR can be a lie, allowing the +call to extract_name() at rfc1025.c:952 to advance the value of p1 +past the calculated end of the record. The makes the calculation +of bytes remaining in the RR underflow to a huge number and results +in a massive heap OOB read and certain crash. + +CVE: CVE-2026-5172 + +Upstream-Status: Backport [ https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=073082ddc0aba7b8efa15a688d6183463b65effa ] + +Signed-off-by: Abhishek Bachiphale + +diff --git a/src/rfc1035.c b/src/rfc1035.c +index f0e1082..7e05fb5 100644 +--- a/src/rfc1035.c ++++ b/src/rfc1035.c +@@ -943,7 +943,8 @@ int extract_addresses(struct dns_header *header, size_t qlen, char *name, time_t + /* Name, extract it then re-encode. */ + int len; + +- if (!extract_name(header, qlen, &p1, name, EXTR_NAME_EXTRACT, 0)) ++ /* rdlen may lie, and extract_name() advances p1 past where it says the record ends. */ ++ if (!extract_name(header, qlen, &p1, name, EXTR_NAME_EXTRACT, 0) || (p1 > endrr)) + { + blockdata_free(addr.rrblock.rrdata); + return 2;