utils-std

commit: 19c387aa62dc66647da6b3ded8f9c255cab086e8
parent 50861bc1e07d70ad37a4a9d6c7d3e769c98a2a83
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Mon, 29 Dec 2025 23:24:47 +0100

cmd/chown: Add depth counter against recursion

Diffstat:
M
cmd/chown.c
21
+++++++++++++++++----

1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/cmd/chown.c b/cmd/chown.c
@@ -28,6 +28,8 @@
 #include <getopt.h>
 #endif
 
+#define DEPTH_MAX 100
+
 const char *argv0 = NULL;
 
 static uid_t user = (uid_t)-1;
@@ -44,7 +46,8 @@ enum chown_follow_symlinks
 };
 
 static int
-do_fchownat(int fd, char *name, char *acc_path, enum chown_follow_symlinks follow_symlinks)
+do_fchownat(
+    int fd, char *name, char *acc_path, enum chown_follow_symlinks follow_symlinks, unsigned depth)
 {
 	struct stat stats;
 	int err = 0;
@@ -52,6 +55,16 @@ do_fchownat(int fd, char *name, char *acc_path, enum chown_follow_symlinks follo
 	int stat_opts = (follow_symlinks == CHOWN_FOLLOW_NO_SYMLINK) ? AT_SYMLINK_NOFOLLOW : 0;
 	int chown_opts = (follow_symlinks == CHOWN_FOLLOW_NO_SYMLINK) ? AT_SYMLINK_NOFOLLOW : 0;
 
+	if(depth == DEPTH_MAX)
+	{
+		fprintf(stderr,
+		        "%s: error: Maximum levels of recursion (%d) reached at file '%s'\n",
+		        argv0,
+		        depth,
+		        acc_path);
+		return 1;
+	}
+
 	if(fstatat(fd, name, &stats, stat_opts) != 0)
 	{
 		fprintf(stderr,
@@ -165,7 +178,7 @@ do_fchownat(int fd, char *name, char *acc_path, enum chown_follow_symlinks follo
 			    (follow_symlinks == CHOWN_FOLLOW_ONE_SYMLINK) ? CHOWN_FOLLOW_NO_SYMLINK : follow_symlinks;
 
 			// No depth counter for now, unlikely to be a problem as symlinks aren't followed
-			int ret = do_fchownat(dir, dp->d_name, new_path, child_follow_symlinks);
+			int ret = do_fchownat(dir, dp->d_name, new_path, child_follow_symlinks, depth + 1);
 			if(ret != 0) return ret;
 		}
 
@@ -310,7 +323,7 @@ main(int argc, char *argv[])
 
 		for(int i = 0; i < argc; i++)
 		{
-			int ret = do_fchownat(AT_FDCWD, argv[i], argv[i], follow_symlinks);
+			int ret = do_fchownat(AT_FDCWD, argv[i], argv[i], follow_symlinks, 0);
 			if(ret != 0) return ret;
 		}
 
@@ -349,7 +362,7 @@ main(int argc, char *argv[])
 
 	for(int i = 1; i < argc; i++)
 	{
-		int ret = do_fchownat(AT_FDCWD, argv[i], argv[i], follow_symlinks);
+		int ret = do_fchownat(AT_FDCWD, argv[i], argv[i], follow_symlinks, 0);
 		if(ret != 0) return ret;
 	}