sudo: backport fix for CVE-2022-43995

(From OE-Core rev: a41a5f310246dcd9dbdb4537d59bc0579c3b1052)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 55 insertions, 0 deletions

diff --git a/meta/recipes-extended/sudo/files/CVE-2022-43995.patch b/meta/recipes-extended/sudo/files/CVE-2022-43995.patch
new file mode 100644
index 0000000000..64dca8c9c6
--- /dev/null
+++ b/meta/recipes-extended/sudo/files/CVE-2022-43995.patch
@@ -0,0 +1,54 @@
+CVE: CVE-2022-43995
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton@arm.com>
+
+From bd209b9f16fcd1270c13db27ae3329c677d48050 Mon Sep 17 00:00:00 2001
+From: "Todd C. Miller" <Todd.Miller@sudo.ws>
+Date: Fri, 28 Oct 2022 07:29:55 -0600
+Subject: [PATCH] Fix CVE-2022-43995, potential heap overflow for passwords < 8
+ characters. Starting with sudo 1.8.0 the plaintext password buffer is
+ dynamically sized so it is not safe to assume that it is at least 9 bytes in
+ size. Found by Hugo Lefeuvre (University of Manchester) with ConfFuzz.
+
+---
+ plugins/sudoers/auth/passwd.c | 11 +++++------
+ 1 file changed, 5 insertions(+), 6 deletions(-)
+
+diff --git a/plugins/sudoers/auth/passwd.c b/plugins/sudoers/auth/passwd.c
+index b2046eca2..0416861e9 100644
+--- a/plugins/sudoers/auth/passwd.c
++++ b/plugins/sudoers/auth/passwd.c
+@@ -63,7 +63,7 @@ sudo_passwd_init(struct passwd *pw, sudo_auth *auth)
+ int
+ sudo_passwd_verify(struct passwd *pw, char *pass, sudo_auth *auth, struct sudo_conv_callback *callback)
+ {
+-    char sav, *epass;
++    char des_pass[9], *epass;
+     char *pw_epasswd = auth->data;
+     size_t pw_len;
+     int matched = 0;
+@@ -75,12 +75,12 @@ sudo_passwd_verify(struct passwd *pw, char *pass, sudo_auth *auth, struct sudo_c
+ 
+     /*
+      * Truncate to 8 chars if standard DES since not all crypt()'s do this.
+-     * If this turns out not to be safe we will have to use OS #ifdef's (sigh).
+      */
+-    sav = pass[8];
+     pw_len = strlen(pw_epasswd);
+-    if (pw_len == DESLEN || HAS_AGEINFO(pw_epasswd, pw_len))
+-       pass[8] = '\0';
++    if (pw_len == DESLEN || HAS_AGEINFO(pw_epasswd, pw_len)) {
++       strlcpy(des_pass, pass, sizeof(des_pass));
++       pass = des_pass;
++    }
+ 
+     /*
+      * Normal UN*X password check.
+@@ -88,7 +88,6 @@ sudo_passwd_verify(struct passwd *pw, char *pass, sudo_auth *auth, struct sudo_c
+      * only compare the first DESLEN characters in that case.
+      */
+     epass = (char *) crypt(pass, pw_epasswd);
+-    pass[8] = sav;
+     if (epass != NULL) {
+        if (HAS_AGEINFO(pw_epasswd, pw_len) && strlen(epass) == DESLEN)
+            matched = !strncmp(pw_epasswd, epass, DESLEN);
diff --git a/meta/recipes-extended/sudo/sudo_1.9.11p3.bb b/meta/recipes-extended/sudo/sudo_1.9.11p3.bb
index ba610ee2e7..fa9cf48196 100644
--- a/meta/recipes-extended/sudo/sudo_1.9.11p3.bb
+++ b/meta/recipes-extended/sudo/sudo_1.9.11p3.bb
@@ -4,6 +4,7 @@ SRC_URI = "https://www.sudo.ws/dist/sudo-${PV}.tar.gz \
            ${@bb.utils.contains('DISTRO_FEATURES', 'pam', '${PAM_SRC_URI}', '', d)} \
            file://0001-sudo.conf.in-fix-conflict-with-multilib.patch \
            file://0001-lib-util-mksigname.c-correctly-include-header-for-ou.patch \
+           file://CVE-2022-43995.patch \
            "
 
 PAM_SRC_URI = "file://sudo.pam"