libpam: Update fix for CVE-2024-10041

Initially, PAM community fixed CVE-2024-10041 in the version v1.6.0 via commit b3020da.
But not all cases were covered with this fix and issues were reported after the release.
In the v1.6.1 release, PAM community fixed these issues via commit b7b9636.
Backport this commit b7b9636, which
Fixes: b3020da ("pam_unix/passverify: always run the helper to obtain shadow password file entries")

Backport from https://github.com/linux-pam/linux-pam/commit/b7b96362087414e52524d3d9d9b3faa21e1db620

(From OE-Core rev: 71035c8c5907f7103ce40b92490a10bd3dde7226)

Signed-off-by: Shubham Kulkarni <skulkarni@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

3 files changed, 79 insertions, 1 deletions

diff --git a/meta/recipes-extended/pam/libpam/CVE-2024-10041.patch b/meta/recipes-extended/pam/libpam/CVE-2024-10041-1.patch
index cb0490299b..cb0490299b 100644
--- a/meta/recipes-extended/pam/libpam/CVE-2024-10041.patch
+++ b/meta/recipes-extended/pam/libpam/CVE-2024-10041-1.patch
diff --git a/meta/recipes-extended/pam/libpam/CVE-2024-10041-2.patch b/meta/recipes-extended/pam/libpam/CVE-2024-10041-2.patch
new file mode 100644
index 0000000000..6070a26266
--- /dev/null
+++ b/meta/recipes-extended/pam/libpam/CVE-2024-10041-2.patch
@@ -0,0 +1,77 @@
+From b7b96362087414e52524d3d9d9b3faa21e1db620 Mon Sep 17 00:00:00 2001
+From: Tobias Stoeckmann <tobias@stoeckmann.org>
+Date: Wed, 24 Jan 2024 18:57:42 +0100
+Subject: [PATCH] pam_unix: try to set uid to 0 for unix_chkpwd
+
+The geteuid check does not cover all cases. If a program runs with
+elevated capabilities like CAP_SETUID then we can still check
+credentials of other users.
+
+Keep logging for future analysis though.
+
+Resolves: https://github.com/linux-pam/linux-pam/issues/747
+Fixes: b3020da7da38 ("pam_unix/passverify: always run the helper to obtain shadow password file entries")
+
+Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
+
+Upstream-Status: Backport [https://github.com/linux-pam/linux-pam/commit/b7b96362087414e52524d3d9d9b3faa21e1db620]
+CVE: CVE-2024-10041
+Signed-off-by: Shubham Kulkarni <skulkarni@mvista.com>
+---
+ modules/pam_unix/pam_unix_acct.c | 17 +++++++++--------
+ modules/pam_unix/support.c       | 14 +++++++-------
+ 2 files changed, 16 insertions(+), 15 deletions(-)
+
+diff --git a/modules/pam_unix/pam_unix_acct.c b/modules/pam_unix/pam_unix_acct.c
+index 8f5ed3e0df..7ffcb9e3f2 100644
+--- a/modules/pam_unix/pam_unix_acct.c
++++ b/modules/pam_unix/pam_unix_acct.c
+@@ -110,14 +110,15 @@ int _unix_run_verify_binary(pam_handle_t *pamh, unsigned long long ctrl,
+       _exit(PAM_AUTHINFO_UNAVAIL);
+     }
+
+-    if (geteuid() == 0) {
+-      /* must set the real uid to 0 so the helper will not error
+-         out if pam is called from setuid binary (su, sudo...) */
+-      if (setuid(0) == -1) {
+-          pam_syslog(pamh, LOG_ERR, "setuid failed: %m");
+-          printf("-1\n");
+-          fflush(stdout);
+-          _exit(PAM_AUTHINFO_UNAVAIL);
++    /* must set the real uid to 0 so the helper will not error
++       out if pam is called from setuid binary (su, sudo...) */
++    if (setuid(0) == -1) {
++      uid_t euid = geteuid();
++      pam_syslog(pamh, euid == 0 ? LOG_ERR : LOG_DEBUG, "setuid failed: %m");
++      if (euid == 0) {
++       printf("-1\n");
++       fflush(stdout);
++       _exit(PAM_AUTHINFO_UNAVAIL);
+       }
+     }
+
+diff --git a/modules/pam_unix/support.c b/modules/pam_unix/support.c
+index d391973f95..69811048e6 100644
+--- a/modules/pam_unix/support.c
++++ b/modules/pam_unix/support.c
+@@ -562,13 +562,13 @@ static int _unix_run_helper_binary(pam_handle_t *pamh, const char *passwd,
+                _exit(PAM_AUTHINFO_UNAVAIL);
+        }
+
+-       if (geteuid() == 0) {
+-          /* must set the real uid to 0 so the helper will not error
+-            out if pam is called from setuid binary (su, sudo...) */
+-         if (setuid(0) == -1) {
+-             D(("setuid failed"));
+-            _exit(PAM_AUTHINFO_UNAVAIL);
+-          }
++       /* must set the real uid to 0 so the helper will not error
++          out if pam is called from setuid binary (su, sudo...) */
++       if (setuid(0) == -1) {
++          D(("setuid failed"));
++          if (geteuid() == 0) {
++             _exit(PAM_AUTHINFO_UNAVAIL);
++          }
+        }
+
+        /* exec binary helper */
diff --git a/meta/recipes-extended/pam/libpam_1.5.2.bb b/meta/recipes-extended/pam/libpam_1.5.2.bb
index 05fe232f6a..567f9741cb 100644
--- a/meta/recipes-extended/pam/libpam_1.5.2.bb
+++ b/meta/recipes-extended/pam/libpam_1.5.2.bb
@@ -27,7 +27,8 @@ SRC_URI = "https://github.com/linux-pam/linux-pam/releases/download/v${PV}/Linux
            file://CVE-2022-28321-0002.patch \
            file://0001-pam_motd-do-not-rely-on-all-filesystems-providing-a-.patch \
            file://CVE-2024-22365.patch \
-           file://CVE-2024-10041.patch \
+           file://CVE-2024-10041-1.patch \
+           file://CVE-2024-10041-2.patch \
            "
 
 SRC_URI[sha256sum] = "e4ec7131a91da44512574268f493c6d8ca105c87091691b8e9b56ca685d4f94d"