diff mbox series

[meta-networking,scarthgap,1/6] dnsmasq: Fix CVE-2026-2291

Message ID 20260520122908.3151647-1-hsimeliere.opensource@witekio.com
State New
Headers show
Series [meta-networking,scarthgap,1/6] dnsmasq: Fix CVE-2026-2291 | expand

Commit Message

Hugo Simeliere May 20, 2026, 12:29 p.m. UTC 
From: "Hugo SIMELIERE (Schneider Electric)" <hsimeliere.opensource@witekio.com>

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

[1] https://sources.debian.org/src/dnsmasq/2.90-4~deb12u2/debian/patches/CVE-2026-2291.patch

Signed-off-by: Hugo SIMELIERE (Schneider Electric) <hsimeliere.opensource@witekio.com>
Reviewed-by: Bruno VERNAY <bruno.vernay@se.com>
---
 .../recipes-support/dnsmasq/dnsmasq_2.90.bb   |  1 +
 .../dnsmasq/files/CVE-2026-2291.patch         | 41 +++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 meta-networking/recipes-support/dnsmasq/files/CVE-2026-2291.patch
diff mbox series

Patch

diff --git a/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb b/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb
index 38fa271dc3..3281404e42 100644
--- a/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb
+++ b/meta-networking/recipes-support/dnsmasq/dnsmasq_2.90.bb
@@ -16,6 +16,7 @@  SRC_URI = "http://www.thekelleys.org.uk/dnsmasq/${@['archive/', ''][float(d.getV
            file://dnsmasq-resolvconf.service \
            file://dnsmasq-noresolvconf.service \
            file://dnsmasq-resolved.conf \
+           file://CVE-2026-2291.patch \
 "
 SRC_URI[sha256sum] = "8f6666b542403b5ee7ccce66ea73a4a51cf19dd49392aaccd37231a2c51b303b"
 
diff --git a/meta-networking/recipes-support/dnsmasq/files/CVE-2026-2291.patch b/meta-networking/recipes-support/dnsmasq/files/CVE-2026-2291.patch
new file mode 100644
index 0000000000..c59fa031f9
--- /dev/null
+++ b/meta-networking/recipes-support/dnsmasq/files/CVE-2026-2291.patch
@@ -0,0 +1,41 @@ 
+From c3059821cd52b423592aeffef7935fdf81035a81 Mon Sep 17 00:00:00 2001
+From: Simon Kelley <simon@thekelleys.org.uk>
+Date: Fri, 10 Apr 2026 16:29:31 +0100
+Subject: [PATCH] Fix buffer overflow in struct bigname. CVE-2026-2291
+
+All buffers capable of holding a domain name should be
+at least MAXDNAME*2 + 1 bytes long, where MAXDNAME is the maximum
+size of a domain name. The accounts for the trailing zero and the
+fact that some characters are escaped in the internal representation
+of a domain name in dnsmasq.
+
+The declaration of struct bigname get this wrong, with the effect
+that a remote attacker capable of asking DNS queries or answering DNS
+queries can cause a large OOB write in the heap.
+
+This was first spotted by Andrew S. Fasano.
+
+CVE: CVE-2026-2291
+Upstream-Status: Backport [https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=014e909f787e808bb35daa546d3f8f3663918de2]
+
+Signed-off-by: Hugo SIMELIERE (Schneider Electric) <hsimeliere.opensource@witekio.com>
+---
+ src/dnsmasq.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/dnsmasq.h b/src/dnsmasq.h
+index e455c3f7..be8cf2ad 100644
+--- a/src/dnsmasq.h
++++ b/src/dnsmasq.h
+@@ -467,7 +467,7 @@ struct interface_name {
+ };
+ 
+ union bigname {
+-  char name[MAXDNAME];
++  char name[(2*MAXDNAME) + 1];
+   union bigname *next; /* freelist */
+ };
+ 
+-- 
+2.43.0
+