From 89ce4e7ca592f5abafc3f25aeaa07d36a7b43a61 Mon Sep 17 00:00:00 2001

From: Panu Matilainen <pmatilai@redhat.com>

Date: Tue, 14 Nov 2023 11:37:48 +0200

Subject: [PATCH] Fix wrong return code on O_DIRECTORY open of invalid symlink

The dir argument to fsmOpenpath() is supposed to be a rough O_DIRECTORY

equivalent, and if the path is actually a misowned symlink it should

return ENOTDIR instead of ELOOP. Makes the resulting error messages

at least a little more comprehensible.

---

 lib/fsm.c | 5 +++--

 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/fsm.c b/lib/fsm.c

index 51f439ef3..091e90554 100644

--- a/lib/fsm.c

+++ b/lib/fsm.c

@@ -304,6 +304,7 @@ static int fsmOpenat(int dirfd, const char *path, int flags, int dir)

     struct stat lsb, sb;

     int sflags = flags | O_NOFOLLOW;

     int fd = openat(dirfd, path, sflags);

+    int ffd = fd;

     /*

      * Only ever follow symlinks by root or target owner. Since we can't

@@ -312,7 +313,7 @@ static int fsmOpenat(int dirfd, const char *path, int flags, int dir)

      * it could've only been the link owner or root.

      */

     if (fd < 0 && errno == ELOOP && flags != sflags) {

-	int ffd = openat(dirfd, path, flags);

+	ffd = openat(dirfd, path, flags);

 	if (ffd >= 0) {

 	    if (fstatat(dirfd, path, &lsb, AT_SYMLINK_NOFOLLOW) == 0) {

 		if (fstat(ffd, &sb) == 0) {

@@ -327,7 +328,7 @@ static int fsmOpenat(int dirfd, const char *path, int flags, int dir)

     }

     /* O_DIRECTORY equivalent */

-    if (dir && fd >= 0 && fstat(fd, &sb) == 0 && !S_ISDIR(sb.st_mode)) {

+    if (dir && ((fd != ffd) || (fd >= 0 && fstat(fd, &sb) == 0 && !S_ISDIR(sb.st_mode)))) {

 	errno = ENOTDIR;

 	fsmClose(&fd;;

     }

-- 

2.43.0