new file mode 100644
@@ -0,0 +1,108 @@
+From 42404548721c653317c911c83d885e2fc7fbca70 Mon Sep 17 00:00:00 2001
+From: Per Jessen <per@jessen.ch>
+Date: Fri, 22 Apr 2022 18:15:36 +0200
+Subject: [PATCH] pam_motd: do not rely on all filesystems providing a filetype
+
+When using scandir() to look for MOTD files to display, we wrongly
+relied on all filesystems providing a filetype. This is a fix to divert
+to lstat() when we have no filetype. To maintain MT safety, it isn't
+possible to use lstat() in the scandir() filter function, so all of the
+filtering has been moved to an additional loop after scanning all the
+motd dirs.
+Also, remove superfluous alphasort from scandir(), we are doing
+a qsort() later.
+
+Resolves: https://github.com/linux-pam/linux-pam/issues/455
+
+Upstream-Status: Backport [https://github.com/linux-pam/linux-pam/commit/42404548721c653317c911c83d885e2fc7fbca70]
+
+Signed-off-by: Per Jessen <per@jessen.ch>
+Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com>
+---
+ modules/pam_motd/pam_motd.c | 49 ++++++++++++++++++++++++++++++-------
+ 1 file changed, 40 insertions(+), 9 deletions(-)
+
+diff --git a/modules/pam_motd/pam_motd.c b/modules/pam_motd/pam_motd.c
+index 6ac8cba2..5ca486e4 100644
+--- a/modules/pam_motd/pam_motd.c
++++ b/modules/pam_motd/pam_motd.c
+@@ -166,11 +166,6 @@ static int compare_strings(const void *a, const void *b)
+ }
+ }
+
+-static int filter_dirents(const struct dirent *d)
+-{
+- return (d->d_type == DT_REG || d->d_type == DT_LNK);
+-}
+-
+ static void try_to_display_directories_with_overrides(pam_handle_t *pamh,
+ char **motd_dir_path_split, unsigned int num_motd_dirs, int report_missing)
+ {
+@@ -199,8 +194,7 @@ static void try_to_display_directories_with_overrides(pam_handle_t *pamh,
+
+ for (i = 0; i < num_motd_dirs; i++) {
+ int rv;
+- rv = scandir(motd_dir_path_split[i], &(dirscans[i]),
+- filter_dirents, alphasort);
++ rv = scandir(motd_dir_path_split[i], &(dirscans[i]), NULL, NULL);
+ if (rv < 0) {
+ if (errno != ENOENT || report_missing) {
+ pam_syslog(pamh, LOG_ERR, "error scanning directory %s: %m",
+@@ -215,6 +209,41 @@ static void try_to_display_directories_with_overrides(pam_handle_t *pamh,
+ if (dirscans_size_total == 0)
+ goto out;
+
++ /* filter out unwanted names, directories, and complement data with lstat() */
++ for (i = 0; i < num_motd_dirs; i++) {
++ struct dirent **d = dirscans[i];
++ for (unsigned int j = 0; j < dirscans_sizes[i]; j++) {
++ int rc;
++ char *fullpath;
++ struct stat s;
++
++ switch(d[j]->d_type) { /* the filetype determines how to proceed */
++ case DT_REG: /* regular files and */
++ case DT_LNK: /* symlinks */
++ continue; /* are good. */
++ case DT_UNKNOWN: /* for file systems that do not provide */
++ /* a filetype, we use lstat() */
++ if (join_dir_strings(&fullpath, motd_dir_path_split[i],
++ d[j]->d_name) <= 0)
++ break;
++ rc = lstat(fullpath, &s);
++ _pam_drop(fullpath); /* free the memory alloc'ed by join_dir_strings */
++ if (rc != 0) /* if the lstat() somehow failed */
++ break;
++
++ if (S_ISREG(s.st_mode) || /* regular files and */
++ S_ISLNK(s.st_mode)) continue; /* symlinks are good */
++ break;
++ case DT_DIR: /* We don't want directories */
++ default: /* nor anything else */
++ break;
++ }
++ _pam_drop(d[j]); /* free memory */
++ d[j] = NULL; /* indicate this one was dropped */
++ dirscans_size_total--;
++ }
++ }
++
+ /* Allocate space for all file names found in the directories, including duplicates. */
+ if ((dirnames_all = calloc(dirscans_size_total, sizeof(*dirnames_all))) == NULL) {
+ pam_syslog(pamh, LOG_CRIT, "failed to allocate dirname array");
+@@ -225,8 +254,10 @@ static void try_to_display_directories_with_overrides(pam_handle_t *pamh,
+ unsigned int j;
+
+ for (j = 0; j < dirscans_sizes[i]; j++) {
+- dirnames_all[i_dirnames] = dirscans[i][j]->d_name;
+- i_dirnames++;
++ if (NULL != dirscans[i][j]) {
++ dirnames_all[i_dirnames] = dirscans[i][j]->d_name;
++ i_dirnames++;
++ }
+ }
+ }
+
+--
+2.39.0
+
@@ -25,6 +25,7 @@ SRC_URI = "${GITHUB_BASE_URI}/download/v${PV}/Linux-PAM-${PV}.tar.xz \
file://run-ptest \
file://pam-volatiles.conf \
file://CVE-2022-28321-0002.patch \
+ file://0001-pam_motd-do-not-rely-on-all-filesystems-providing-a-.patch \
"
SRC_URI[sha256sum] = "e4ec7131a91da44512574268f493c6d8ca105c87091691b8e9b56ca685d4f94d"