shadow: backport patch to fix CVE-2023-29383

The fix of CVE-2023-29383.patch contains a bug that it rejects all
characters that are not control ones, so backup another patch named
"0001-Overhaul-valid_field.patch" from upstream to fix it.

(From OE-Core rev: c5da9027cc73484936f4f82a37c32348cee1e229)

Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 118 insertions, 0 deletions

diff --git a/meta/recipes-extended/shadow/files/0001-Overhaul-valid_field.patch b/meta/recipes-extended/shadow/files/0001-Overhaul-valid_field.patch
new file mode 100644
index 0000000000..ac08be515b
--- /dev/null
+++ b/meta/recipes-extended/shadow/files/0001-Overhaul-valid_field.patch
@@ -0,0 +1,65 @@
+From 2eaea70111f65b16d55998386e4ceb4273c19eb4 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
+Date: Fri, 31 Mar 2023 14:46:50 +0200
+Subject: [PATCH] Overhaul valid_field()
+
+e5905c4b ("Added control character check") introduced checking for
+control characters but had the logic inverted, so it rejects all
+characters that are not control ones.
+
+Cast the character to `unsigned char` before passing to the character
+checking functions to avoid UB.
+
+Use strpbrk(3) for the illegal character test and return early.
+
+Upstream-Status: Backport [https://github.com/shadow-maint/shadow/commit/2eaea70111f65b16d55998386e4ceb4273c19eb4]
+
+Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
+---
+ lib/fields.c | 24 ++++++++++--------------
+ 1 file changed, 10 insertions(+), 14 deletions(-)
+
+diff --git a/lib/fields.c b/lib/fields.c
+index fb51b582..53929248 100644
+--- a/lib/fields.c
++++ b/lib/fields.c
+@@ -37,26 +37,22 @@ int valid_field (const char *field, const char *illegal)
+ 
+        /* For each character of field, search if it appears in the list
+         * of illegal characters. */
++       if (illegal && NULL != strpbrk (field, illegal)) {
++               return -1;
++       }
++
++       /* Search if there are non-printable or control characters */
+        for (cp = field; '\0' != *cp; cp++) {
+-               if (strchr (illegal, *cp) != NULL) {
++               unsigned char c = *cp;
++               if (!isprint (c)) {
++                       err = 1;
++               }
++               if (iscntrl (c)) {
+                        err = -1;
+                        break;
+                }
+        }
+ 
+-       if (0 == err) {
+-               /* Search if there are non-printable or control characters */
+-               for (cp = field; '\0' != *cp; cp++) {
+-                       if (!isprint (*cp)) {
+-                               err = 1;
+-                       }
+-                       if (!iscntrl (*cp)) {
+-                               err = -1;
+-                               break;
+-                       }
+-               }
+-       }
+-
+        return err;
+ }
+ 
+-- 
+2.34.1
+
diff --git a/meta/recipes-extended/shadow/files/CVE-2023-29383.patch b/meta/recipes-extended/shadow/files/CVE-2023-29383.patch
new file mode 100644
index 0000000000..f53341d3fc
--- /dev/null
+++ b/meta/recipes-extended/shadow/files/CVE-2023-29383.patch
@@ -0,0 +1,53 @@
+From e5905c4b84d4fb90aefcd96ee618411ebfac663d Mon Sep 17 00:00:00 2001
+From: tomspiderlabs <128755403+tomspiderlabs@users.noreply.github.com>
+Date: Thu, 23 Mar 2023 23:39:38 +0000
+Subject: [PATCH] Added control character check
+
+Added control character check, returning -1 (to "err") if control characters are present.
+
+CVE: CVE-2023-29383
+Upstream-Status: Backport
+
+Reference to upstream:
+https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d
+
+Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
+---
+ lib/fields.c | 11 +++++++----
+ 1 file changed, 7 insertions(+), 4 deletions(-)
+
+diff --git a/lib/fields.c b/lib/fields.c
+index 640be931..fb51b582 100644
+--- a/lib/fields.c
++++ b/lib/fields.c
+@@ -21,9 +21,9 @@
+  *
+  * The supplied field is scanned for non-printable and other illegal
+  * characters.
+- *  + -1 is returned if an illegal character is present.
+- *  +  1 is returned if no illegal characters are present, but the field
+- *       contains a non-printable character.
++ *  + -1 is returned if an illegal or control character is present.
++ *  +  1 is returned if no illegal or control characters are present,
++ *       but the field contains a non-printable character.
+  *  +  0 is returned otherwise.
+  */
+ int valid_field (const char *field, const char *illegal)
+@@ -45,10 +45,13 @@ int valid_field (const char *field, const char *illegal)
+        }
+ 
+        if (0 == err) {
+-               /* Search if there are some non-printable characters */
++               /* Search if there are non-printable or control characters */
+                for (cp = field; '\0' != *cp; cp++) {
+                        if (!isprint (*cp)) {
+                                err = 1;
++                       }
++                       if (!iscntrl (*cp)) {
++                               err = -1;
+                                break;
+                        }
+                }
+-- 
+2.34.1
+