libksba: fix CVE-2022-47629

Libksba before 1.6.3 is prone to an integer overflow vulnerability in the CRL signature parser.

CVE: CVE-2022-47926

References: https://nvd.nist.gov/vuln/detail/CVE-2022-47629

Signed-off-by: Yogita Urade <yogita.urade@windriver.com>

2 files changed, 74 insertions, 1 deletions

diff --git a/meta/recipes-support/libksba/libksba/0001-Fix-an-integer-overflow-in-the-CRL-signature-parser.patch b/meta/recipes-support/libksba/libksba/0001-Fix-an-integer-overflow-in-the-CRL-signature-parser.patch
new file mode 100644
index 0000000000..8c0080d56b
--- /dev/null
+++ b/meta/recipes-support/libksba/libksba/0001-Fix-an-integer-overflow-in-the-CRL-signature-parser.patch
@@ -0,0 +1,72 @@
+From f61a5ea4e0f6a80fd4b28ef0174bee77793cf070 Mon Sep 17 00:00:00 2001
+From: Werner Koch <wk@gnupg.org>
+Date: Tue, 22 Nov 2022 16:36:46 +0100
+Subject: [PATCH] Fix an integer overflow in the CRL signature parser.
+
+* src/crl.c (parse_signature): N+N2 now checked for overflow.
+
+* src/ocsp.c (parse_response_extensions): Do not accept too large
+values.
+(parse_single_extensions): Ditto.
+--
+
+The second patch is an extra safegourd not related to the reported
+bug.
+
+CVE: CVE-2022-47629
+
+Upstream-Status: Backport [https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libksba.git;a=commit;h=f61a5ea4e0f6a80fd4b28ef0174bee77793cf070]
+
+GnuPG-bug-id: 6284
+Reported-by: Joseph Surin, elttam
+---
+ src/crl.c  |  2 +-
+ src/ocsp.c | 12 ++++++++++++
+ 2 files changed, 13 insertions(+), 1 deletion(-)
+
+diff --git a/src/crl.c b/src/crl.c
+index 9f71c85..2e6ca29 100644
+--- a/src/crl.c
++++ b/src/crl.c
+@@ -1349,7 +1349,7 @@ parse_signature (ksba_crl_t crl)
+          && !ti.is_constructed) )
+     return gpg_error (GPG_ERR_INV_CRL_OBJ);
+   n2 = ti.nhdr + ti.length;
+-  if (n + n2 >= DIM(tmpbuf))
++  if (n + n2 >= DIM(tmpbuf) || (n + n2) < n)
+     return gpg_error (GPG_ERR_TOO_LARGE);
+   memcpy (tmpbuf+n, ti.buf, ti.nhdr);
+   err = read_buffer (crl->reader, tmpbuf+n+ti.nhdr, ti.length);
+diff --git a/src/ocsp.c b/src/ocsp.c
+index d4cba04..657d15f 100644
+--- a/src/ocsp.c
++++ b/src/ocsp.c
+@@ -721,6 +721,12 @@ parse_response_extensions (ksba_ocsp_t ocsp,
+               || memcmp (ocsp->nonce, data, ti.length))
+             ocsp->bad_nonce = 1;
+         }
++      if (ti.length > (1<<24))
++        {
++          /* Bail out on much too large objects.  */
++          err = gpg_error (GPG_ERR_BAD_BER);
++          goto leave;
++        }
+       ex = xtrymalloc (sizeof *ex + strlen (oid) + ti.length);
+       if (!ex)
+         {
+@@ -788,6 +794,12 @@ parse_single_extensions (struct ocsp_reqitem_s *ri,
+       err = parse_octet_string (&data, &datalen, &ti);
+       if (err)
+         goto leave;
++      if (ti.length > (1<<24))
++        {
++          /* Bail out on much too large objects.  */
++          err = gpg_error (GPG_ERR_BAD_BER);
++          goto leave;
++        }
+       ex = xtrymalloc (sizeof *ex + strlen (oid) + ti.length);
+       if (!ex)
+         {
+-- 
+2.32.0
+
diff --git a/meta/recipes-support/libksba/libksba_1.6.2.bb b/meta/recipes-support/libksba/libksba_1.6.2.bb
index f6ecb9aec4..d0ee8475f8 100644
--- a/meta/recipes-support/libksba/libksba_1.6.2.bb
+++ b/meta/recipes-support/libksba/libksba_1.6.2.bb
@@ -22,7 +22,8 @@ inherit autotools binconfig-disabled pkgconfig texinfo
 
 UPSTREAM_CHECK_URI = "https://gnupg.org/download/index.html"
 SRC_URI = "${GNUPG_MIRROR}/${BPN}/${BPN}-${PV}.tar.bz2 \
-           file://ksba-add-pkgconfig-support.patch"
+           file://ksba-add-pkgconfig-support.patch \
+           file://0001-Fix-an-integer-overflow-in-the-CRL-signature-parser.patch"
 
 SRC_URI[sha256sum] = "fce01ccac59812bddadffacff017dac2e4762bdb6ebc6ffe06f6ed4f6192c971"