[OE-core][scarthgap][PATCH] libxml2: Fix CVE-2026-11979

["Devansh Patel -X (devanshp - E INFOCHIPS PRIVATE LIMITED at Cisco)" <devanshp@cisco.com>]

From: Devansh Patel <devanshp@cisco.com>

This patch applies the upstream fix as referenced in [2],
using the commit shown in [1].

[1] https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503f777a72e
[2] https://nvd.nist.gov/vuln/detail/CVE-2026-11979

Signed-off-by: Devansh Patel <devanshp@cisco.com>
---
 .../libxml/libxml2/CVE-2026-11979.patch       | 70 +++++++++++++++++++
 meta/recipes-core/libxml/libxml2_2.12.10.bb   |  1 +
 2 files changed, 71 insertions(+)
 create mode 100644 meta/recipes-core/libxml/libxml2/CVE-2026-11979.patch

diff --git a/meta/recipes-core/libxml/libxml2/CVE-2026-11979.patch b/meta/recipes-core/libxml/libxml2/CVE-2026-11979.patch
new file mode 100644
index 0000000000..427026b345
--- /dev/null
+++ b/meta/recipes-core/libxml/libxml2/CVE-2026-11979.patch
@@ -0,0 +1,70 @@
+From d8566dd918c612078dfb3ee1a95d7bb6f0656bfe Mon Sep 17 00:00:00 2001
+From: Daniel Garcia Moreno <daniel.garcia@suse.com>
+Date: Fri, 22 May 2026 12:21:20 +0200
+Subject: [PATCH] xmlcatalog: overflow check for large --shell commands
+
+Fix https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1124
+
+CVE: CVE-2026-11979
+Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503f777a72e]
+
+Backport Changes:
+- The commit modifies test/catalogs/test.sh.
+- test/catalogs/test.sh does not exist in the libxml2 v2.12.10
+  source used in Scarthgap and was introduced later version
+  libxml2 v2.14.0 [1].
+- The test changes were omitted; only the required fix in
+  xmlcatalog.c was backported.
+
+[1] https://gitlab.gnome.org/GNOME/libxml2/-/commit/f06fc933cdaea2ce8e9cea275fdbf4edb85f9837
+
+(cherry picked from commit c2e233fc1b341685fc99621b2768b503f777a72e)
+Signed-off-by: Devansh Patel <devanshp@cisco.com>
+---
+ xmlcatalog.c | 16 ++++++++++++++++
+ 1 file changed, 16 insertions(+)
+
+diff --git a/xmlcatalog.c b/xmlcatalog.c
+index 588802b41..51569b879 100644
+--- a/xmlcatalog.c
++++ b/xmlcatalog.c
+@@ -114,6 +114,12 @@ static void usershell(void) {
+ 	       (*cur != '\n') && (*cur != '\r')) {
+ 	    if (*cur == 0)
+ 		break;
++            /* Do not read beyond the command array capacity */
++            if (i >= (int)sizeof(command) - 2) {
++                printf("Invalid command %s\n", cur);
++                i = 0;
++                break;
++            }
+ 	    command[i++] = *cur++;
+ 	}
+ 	command[i] = 0;
+@@ -131,6 +137,11 @@ static void usershell(void) {
+ 	while ((*cur != '\n') && (*cur != '\r') && (*cur != 0)) {
+ 	    if (*cur == 0)
+ 		break;
++            if (i >= (int)sizeof(arg) - 2) {
++                printf("Invalid arg %s\n", arg);
++                i = 0;
++                break;
++            }
+ 	    arg[i++] = *cur++;
+ 	}
+ 	arg[i] = 0;
+@@ -143,6 +154,11 @@ static void usershell(void) {
+ 	cur = arg;
+ 	memset(argv, 0, sizeof(argv));
+ 	while (*cur != 0) {
++            if (i >= (int)sizeof(argv) / (int)sizeof(char*)) {
++                printf("Too much arguments\n");
++                break;
++            }
++
+ 	    while ((*cur == ' ') || (*cur == '\t')) cur++;
+ 	    if (*cur == '\'') {
+ 		cur++;
+-- 
+2.35.6
+
diff --git a/meta/recipes-core/libxml/libxml2_2.12.10.bb b/meta/recipes-core/libxml/libxml2_2.12.10.bb
index 2bfa78324f..d476ba14b6 100644
--- a/meta/recipes-core/libxml/libxml2_2.12.10.bb
+++ b/meta/recipes-core/libxml/libxml2_2.12.10.bb
@@ -31,6 +31,7 @@ SRC_URI += "http://www.w3.org/XML/Test/xmlts20130923.tar;subdir=${BP};name=testt
            file://CVE-2026-0992-02.patch \
            file://CVE-2026-0992-03.patch \
            file://CVE-2026-1757.patch \
+           file://CVE-2026-11979.patch \
            "
 
 SRC_URI[archive.sha256sum] = "c3d8c0c34aa39098f66576fe51969db12a5100b956233dc56506f7a8679be995"
-- 
2.44.4