pam: Fix for CVE-2024-22365

Upstream-Status: Backport from https://github.com/linux-pam/linux-pam/commit/031bb5a5d0d950253b68138b498dc93be69a64cb

(From OE-Core rev: 6d4c14e1053089a67a38a8de95625e4ba3fbc32a)

Signed-off-by: Guðni Már Gilbert <gudni.m.g@gmail.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 66 insertions, 0 deletions

diff --git a/meta/recipes-extended/pam/libpam/CVE-2024-22365.patch b/meta/recipes-extended/pam/libpam/CVE-2024-22365.patch
new file mode 100644
index 0000000000..e4ec862dc5
--- /dev/null
+++ b/meta/recipes-extended/pam/libpam/CVE-2024-22365.patch
@@ -0,0 +1,65 @@
+From 84f378d3b8573828e7ccc54b54b5e128aa993748 Mon Sep 17 00:00:00 2001
+From: Matthias Gerstner <matthias.gerstner@suse.de>
+Date: Wed, 27 Dec 2023 14:01:59 +0100
+Subject: [PATCH] pam_namespace: protect_dir(): use O_DIRECTORY to prevent
+ local DoS situations
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Without O_DIRECTORY the path crawling logic is subject to e.g. FIFOs
+being placed in user controlled directories, causing the PAM module to
+block indefinitely during `openat()`.
+
+Pass O_DIRECTORY to cause the `openat()` to fail if the path does not
+refer to a directory.
+
+With this the check whether the final path element is a directory
+becomes unnecessary, drop it.
+
+Upstream-Status: Backport [https://github.com/linux-pam/linux-pam/commit/031bb5a5d0d950253b68138b498dc93be69a64cb]
+CVE: CVE-2024-22365
+Signed-off-by: Guðni Már Gilbert  <gudni.m.g@gmail.com>
+---
+ modules/pam_namespace/pam_namespace.c | 18 +-----------------
+ 1 file changed, 1 insertion(+), 17 deletions(-)
+
+diff --git a/modules/pam_namespace/pam_namespace.c b/modules/pam_namespace/pam_namespace.c
+index f34ce934..ef856443 100644
+--- a/modules/pam_namespace/pam_namespace.c
++++ b/modules/pam_namespace/pam_namespace.c
+@@ -1194,7 +1194,7 @@ static int protect_dir(const char *path, mode_t mode, int do_mkdir,
+        int dfd = AT_FDCWD;
+        int dfd_next;
+        int save_errno;
+-       int flags = O_RDONLY;
++       int flags = O_RDONLY | O_DIRECTORY;
+        int rv = -1;
+        struct stat st;
+ 
+@@ -1248,22 +1248,6 @@ static int protect_dir(const char *path, mode_t mode, int do_mkdir,
+                rv = openat(dfd, dir, flags);
+        }
+ 
+-       if (rv != -1) {
+-               if (fstat(rv, &st) != 0) {
+-                       save_errno = errno;
+-                       close(rv);
+-                       rv = -1;
+-                       errno = save_errno;
+-                       goto error;
+-               }
+-               if (!S_ISDIR(st.st_mode)) {
+-                       close(rv);
+-                       errno = ENOTDIR;
+-                       rv = -1;
+-                       goto error;
+-               }
+-       }
+-
+        if (flags & O_NOFOLLOW) {
+                /* we are inside user-owned dir - protect */
+                if (protect_mount(rv, p, idata) == -1) {
+-- 
+2.43.0
+
diff --git a/meta/recipes-extended/pam/libpam_1.5.3.bb b/meta/recipes-extended/pam/libpam_1.5.3.bb
index ef32d19f3d..bcaa84c9a5 100644
--- a/meta/recipes-extended/pam/libpam_1.5.3.bb
+++ b/meta/recipes-extended/pam/libpam_1.5.3.bb
@@ -26,6 +26,7 @@ SRC_URI = "${GITHUB_BASE_URI}/download/v${PV}/Linux-PAM-${PV}.tar.xz \
            file://pam-volatiles.conf \
            file://0001-pam_namespace-include-stdint-h.patch \
            file://0001-pam_pwhistory-fix-passing-NULL-filename-argument-to-.patch \
+           file://CVE-2024-22365.patch \
            "
 
 SRC_URI[sha256sum] = "7ac4b50feee004a9fa88f1dfd2d2fa738a82896763050cd773b3c54b0a818283"