unzip: fix CVE-2021-4217

Avoid a null pointer dereference.

(From OE-Core rev: 357791da82f767ad695e4476aa12fea3d7db5e04)

Signed-off-by: Joe Slater <joe.slater@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
(cherry picked from commit 36db85b9b127e5a9f5d3d6e428168cf597ab95f3)
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/unzip/unzip/CVE-2021-4217.patch

+From 731d698377dbd1f5b1b90efeb8094602ed59fc40 Mon Sep 17 00:00:00 2001
+From: Nils Bars <nils.bars@t-online.de>
+Date: Mon, 17 Jan 2022 16:53:16 +0000
+Subject: [PATCH] Fix null pointer dereference and use of uninitialized data
+
+This fixes a bug that causes use of uninitialized heap data if `readbuf` fails
+to read as many bytes as indicated by the extra field length attribute.
+Furthermore, this fixes a null pointer dereference if an archive contains an
+`EF_UNIPATH` extra field but does not have a filename set.
+---
+ fileio.c  | 5 ++++-
+ process.c | 6 +++++-
+ 2 files changed, 9 insertions(+), 2 deletions(-) 
+---
+
+Patch from:
+https://bugs.launchpad.net/ubuntu/+source/unzip/+bug/1957077
+https://launchpadlibrarian.net/580782282/0001-Fix-null-pointer-dereference-and-use-of-uninitialized-data.patch
+Regenerated to apply without offsets.
+
+CVE: CVE-2021-4217
+
+Upstream-Status: Pending [infozip upstream inactive]
+
+Signed-off-by: Joe Slater <joe.slater@windriver.com>
+
+
+diff --git a/fileio.c b/fileio.c
+index 14460f3..1dc319e 100644
+--- a/fileio.c
++++ b/fileio.c
+@@ -2301,8 +2301,11 @@ int do_string(__G__ length, option)   /* return PK-type error code */
+             seek_zipf(__G__ G.cur_zipfile_bufstart - G.extra_bytes +
+                       (G.inptr-G.inbuf) + length);
+         } else {
+-            if (readbuf(__G__ (char *)G.extra_field, length) == 0)
++            unsigned bytes_read = readbuf(__G__ (char *)G.extra_field, length);
++            if (bytes_read == 0)
+                 return PK_EOF;
++            if (bytes_read != length)
++                return PK_ERR;
+             /* Looks like here is where extra fields are read */
+             if (getZip64Data(__G__ G.extra_field, length) != PK_COOL)
+             {
+diff --git a/process.c b/process.c
+index 5f8f6c6..de843a5 100644
+--- a/process.c
++++ b/process.c
+@@ -2058,10 +2058,14 @@ int getUnicodeData(__G__ ef_buf, ef_len)
+           G.unipath_checksum = makelong(offset + ef_buf);
+           offset += 4;
+ 
++          if (!G.filename_full) {
++            /* Check if we have a unicode extra section but no filename set */
++            return PK_ERR;
++          }
++
+           /*
+            * Compute 32-bit crc
+            */
+-
+           chksum = crc32(chksum, (uch *)(G.filename_full),
+                          strlen(G.filename_full));
+ 
+-- 
+2.32.0
+

meta/recipes-extended/unzip/unzip_6.0.bb

@@ -26,6 +26,7 @@ SRC_URI = "${SOURCEFORGE_MIRROR}/infozip/UnZip%206.x%20%28latest%29/UnZip%206.0/
 	file://CVE-2019-13232_p1.patch \
 	file://CVE-2019-13232_p2.patch \
 	file://CVE-2019-13232_p3.patch \
+        file://CVE-2021-4217.patch \
 "
 UPSTREAM_VERSION_UNKNOWN = "1"