dnsmasq: Fix CVE-2026-5172

Pick patch from [1] dnsmasq 2.90 debian bookworm pacthes.

[1] https://sources.debian.org/src/dnsmasq/2.90-4~deb12u2/debian/patches/CVE-2026-5172.patch

Signed-off-by: Hugo SIMELIERE (Schneider Electric) <hsimeliere.opensource@witekio.com>
Reviewed-by: Bruno VERNAY <bruno.vernay@se.com>
Signed-off-by: Anuj Mittal <anuj.mittal@oss.qualcomm.com>

2 files changed, 40 insertions, 0 deletions

diff --git a/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb b/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb
index 4e548f6e59..7830c9c81f 100644
--- a/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb
+++ b/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb
@@ -19,6 +19,7 @@ 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] = "8f6666b542403b5ee7ccce66ea73a4a51cf19dd49392aaccd37231a2c51b303b"
 
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..58aac87e4e
--- /dev/null
+++ b/meta-networking/recipes-support/dnsmasq/files/CVE-2026-5172.patch
@@ -0,0 +1,39 @@
+From f158664062e049ec4604f6e772551a00575011f4 Mon Sep 17 00:00:00 2001
+From: Simon Kelley <simon@thekelleys.org.uk>
+Date: Mon, 30 Mar 2026 16:24:33 +0100
+Subject: [PATCH] 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: Hugo SIMELIERE (Schneider Electric) <hsimeliere.opensource@witekio.com>
+---
+ src/rfc1035.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/src/rfc1035.c b/src/rfc1035.c
+index 387d894a..32dc5711 100644
+--- a/src/rfc1035.c
++++ b/src/rfc1035.c
+@@ -932,7 +932,8 @@ 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, 1, 0))
++                             /* rdlen may lie, and extract_name() advances p1 past where it says the record ends. */
++                             if (!extract_name(header, qlen, &p1, name, 1, 0) || (p1 > endrr))
+                                {
+                                  blockdata_free(addr.rrblock.rrdata);
+                                  return 2;
+-- 
+2.43.0
+