From a5b7a9a8bec6a7f2162850449b1ff29c1fde2826 Mon Sep 17 00:00:00 2001
From: smitsohu <smitsohu@gmail.com>
Date: Fri, 12 Oct 2018 18:33:17 +0200
Subject: clean homedir pathname

fixes #2137 and similar issues with the /proc/self/mountinfo checks
---
 src/firejail/firejail.h |  1 +
 src/firejail/main.c     |  5 ++---
 src/firejail/util.c     | 42 +++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/src/firejail/firejail.h b/src/firejail/firejail.h
index 1d74dc8dc..cae767667 100644
--- a/src/firejail/firejail.h
+++ b/src/firejail/firejail.h
@@ -522,6 +522,7 @@ int is_link(const char *fname);
 void trim_trailing_slash_or_dot(char *path);
 char *line_remove_spaces(const char *buf);
 char *split_comma(char *str);
+char *clean_pathname(const char *path);
 void check_unsigned(const char *str, const char *msg);
 int find_child(pid_t parent, pid_t *child);
 void check_private_dir(void);
diff --git a/src/firejail/main.c b/src/firejail/main.c
index 123fe96a1..315a7260a 100644
--- a/src/firejail/main.c
+++ b/src/firejail/main.c
@@ -233,9 +233,8 @@ static void init_cfg(int argc, char **argv) {
 	// build home directory name
 	cfg.homedir = NULL;
 	if (pw->pw_dir != NULL) {
-		cfg.homedir = strdup(pw->pw_dir);
-		if (!cfg.homedir)
-			errExit("strdup");
+		cfg.homedir = clean_pathname(pw->pw_dir);
+		assert(cfg.homedir);
 	}
 	else {
 		fprintf(stderr, "Error: user %s doesn't have a user directory assigned\n", cfg.username);
diff --git a/src/firejail/util.c b/src/firejail/util.c
index ae07a42b0..0d1418b43 100644
--- a/src/firejail/util.c
+++ b/src/firejail/util.c
@@ -533,6 +533,46 @@ char *split_comma(char *str) {
 }
 
 
+// remove consecutive and trailing slashes
+// and return allocated memory
+// e.g. /home//user/ -> /home/user
+char *clean_pathname(const char *path) {
+	assert(path);
+	size_t len = strlen(path);
+	char *rv = calloc(len + 1, 1);
+	if (!rv)
+		errExit("calloc");
+
+	if (len > 0) {
+		int i, j, cnt;
+		for (i = 0, j = 0, cnt = 0; i < len; i++) {
+			if (path[i] == '/')
+				cnt++;
+			else
+				cnt = 0;
+
+			if (cnt < 2) {
+				rv[j] = path[i];
+				j++;
+			}
+		}
+
+		// remove a trailing slash
+		if (j > 1 && rv[j - 1] == '/')
+			rv[j - 1] = '\0';
+
+		size_t new_len = strlen(rv);
+		if (new_len < len) {
+			rv = realloc(rv, new_len + 1);
+			if (!rv)
+				errExit("realloc");
+		}
+	}
+
+	return rv;
+}
+
+
 void check_unsigned(const char *str, const char *msg) {
 	EUID_ASSERT();
 	const char *ptr = str;
@@ -656,7 +696,7 @@ void extract_command_name(int index, char **argv) {
 	// command name is a substring of cfg.command_name
 	if (basename != cfg.command_name || *ptr != '\0') {
 		*ptr = '\0';
-		
+
 		basename = strdup(basename);
 		if (!basename)
 			errExit("strdup");
-- 
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