[OE-core][scarthgap][PATCH 2/2] patch: Fix CVE-2026-56288

["Hetvi Thakar -X (hthakar - E INFOCHIPS PRIVATE LIMITED at Cisco)" <hthakar@cisco.com>]

From: Hetvi Thakar <hthakar@cisco.com>

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

[1] https://cgit.git.savannah.gnu.org/cgit/patch.git/commit/?id=e6d6a4e021660679d7fc9150f981d4920f722313
[2] https://nvd.nist.gov/vuln/detail/CVE-2026-56288

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
---
 .../patch/patch/CVE-2026-56288.patch          | 75 +++++++++++++++++++
 meta/recipes-devtools/patch/patch_2.7.6.bb    |  1 +
 2 files changed, 76 insertions(+)
 create mode 100644 meta/recipes-devtools/patch/patch/CVE-2026-56288.patch

diff --git a/meta/recipes-devtools/patch/patch/CVE-2026-56288.patch b/meta/recipes-devtools/patch/patch/CVE-2026-56288.patch
new file mode 100644
index 0000000000..03e1211f2e
--- /dev/null
+++ b/meta/recipes-devtools/patch/patch/CVE-2026-56288.patch
@@ -0,0 +1,75 @@
+From f98fd4b5f696d1fcc9d86f81555370cf4b21150f Mon Sep 17 00:00:00 2001
+From: Paul Eggert <eggert@cs.ucla.edu>
+Date: Tue, 21 Apr 2026 10:05:02 -0700
+Subject: [PATCH] Avoid null pointer derefence with bad hunks
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Problem reported by Michał Majchrowicz.
+* src/pch.c (another_hunk): Keep chars_read positive
+even with malformed hunks.
+
+CVE: CVE-2026-56288
+Upstream-Status: Backport [https://cgit.git.savannah.gnu.org/cgit/patch.git/commit/?id=e6d6a4e021660679d7fc9150f981d4920f722313]
+
+(cherry picked from commit e6d6a4e021660679d7fc9150f981d4920f722313)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ src/pch.c | 15 ++++++++++-----
+ 1 file changed, 10 insertions(+), 5 deletions(-)
+
+diff --git a/src/pch.c b/src/pch.c
+index 6f9f36f..0a31f72 100644
+--- a/src/pch.c
++++ b/src/pch.c
+@@ -1728,7 +1728,8 @@ another_hunk (enum diff difftype, bool rev)
+ 		    p_end = filldst-1;
+ 		    malformed ();
+ 		}
+-		chars_read -= fillsrc == p_ptrn_lines && incomplete_line ();
++		chars_read -= (1 < chars_read && fillsrc == p_ptrn_lines
++			       && incomplete_line ());
+ 		p_Char[fillsrc] = ch;
+ 		p_line[fillsrc] = s;
+ 		p_len[fillsrc++] = chars_read;
+@@ -1745,7 +1746,8 @@ another_hunk (enum diff difftype, bool rev)
+ 		    malformed ();
+ 		}
+ 		context++;
+-		chars_read -= fillsrc == p_ptrn_lines && incomplete_line ();
++		chars_read -= (1 < chars_read && fillsrc == p_ptrn_lines
++			       && incomplete_line ());
+ 		p_Char[fillsrc] = ch;
+ 		p_line[fillsrc] = s;
+ 		p_len[fillsrc++] = chars_read;
+@@ -1765,7 +1767,8 @@ another_hunk (enum diff difftype, bool rev)
+ 		    p_end = fillsrc-1;
+ 		    malformed ();
+ 		}
+-		chars_read -= filldst == p_end && incomplete_line ();
++		chars_read -= (1 < chars_read && filldst == p_end
++			       && incomplete_line ());
+ 		p_Char[filldst] = ch;
+ 		p_line[filldst] = s;
+ 		p_len[filldst++] = chars_read;
+@@ -1852,7 +1855,8 @@ another_hunk (enum diff difftype, bool rev)
+ 	    if (buf[0] != '<' || (buf[1] != ' ' && buf[1] != '\t'))
+ 	      fatal ("'<' followed by space or tab expected at line %s of patch",
+ 		     format_linenum (numbuf0, p_input_line));
+-	    chars_read -= 2 + (i == p_ptrn_lines && incomplete_line ());
++	    chars_read -= 2 + (3 < chars_read && i == p_ptrn_lines
++			       && incomplete_line ());
+ 	    p_len[i] = chars_read;
+ 	    p_line[i] = savebuf (buf + 2, chars_read);
+ 	    if (chars_read && ! p_line[i]) {
+@@ -1897,7 +1901,8 @@ another_hunk (enum diff difftype, bool rev)
+ 	    if (buf[0] != '>' || (buf[1] != ' ' && buf[1] != '\t'))
+ 	      fatal ("'>' followed by space or tab expected at line %s of patch",
+ 		     format_linenum (numbuf0, p_input_line));
+-	    chars_read -= 2 + (i == p_end && incomplete_line ());
++	    chars_read -= 2 + (3 < chars_read && i == p_end
++			       && incomplete_line ());
+ 	    p_len[i] = chars_read;
+ 	    p_line[i] = savebuf (buf + 2, chars_read);
+ 	    if (chars_read && ! p_line[i]) {
diff --git a/meta/recipes-devtools/patch/patch_2.7.6.bb b/meta/recipes-devtools/patch/patch_2.7.6.bb
index 74d9085c6b..53e96dea0f 100644
--- a/meta/recipes-devtools/patch/patch_2.7.6.bb
+++ b/meta/recipes-devtools/patch/patch_2.7.6.bb
@@ -12,6 +12,7 @@ SRC_URI += "file://0001-Unset-need_charset_alias-when-building-for-musl.patch \
             file://0001-Don-t-leak-temporary-file-on-failed-multi-file-ed.patch \
             file://CVE-2019-20633.patch \
             file://CVE-2026-56289.patch \
+            file://CVE-2026-56288.patch \
 "
 
 SRC_URI[md5sum] = "4c68cee989d83c87b00a3860bcd05600"
-- 
2.35.6