[PATCH v2] samples/landlock: Fix possible NULL dereference in parse_path()

[Gax-c]

From: Zichen Xie <zichenxie0106 at gmail.com>

malloc() may return NULL, leading to NULL dereference.
Add a NULL check.

Fixes: ba84b0bf5a16 ("samples/landlock: Add a sandbox manager example")
Signed-off-by: Zichen Xie <zichenxie0106 at gmail.com>
Cc: stable at vger.kernel.org
---
v2: Modify logic & Add Fixes tag.
---
 samples/landlock/sandboxer.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
index 57565dfd74a2..ef2a34173d84 100644
--- a/samples/landlock/sandboxer.c
+++ b/samples/landlock/sandboxer.c
@@ -91,6 +91,9 @@ static int parse_path(char *env_path, const char ***const path_list)
 		}
 	}
 	*path_list = malloc(num_paths * sizeof(**path_list));
+	if (*path_list == NULL)
+		return -1;
+
 	for (i = 0; i < num_paths; i++)
 		(*path_list)[i] = strsep(&env_path, ENV_DELIMITER);
 
@@ -127,6 +130,11 @@ static int populate_ruleset_fs(const char *const env_var, const int ruleset_fd,
 	env_path_name = strdup(env_path_name);
 	unsetenv(env_var);
 	num_paths = parse_path(env_path_name, &path_list);
+	if (num_paths == -1) {
+		fprintf(stderr, "Failed to allocate memory\n");
+		ret = 1;
+		goto out_free_name;
+	}
 	if (num_paths == 1 && path_list[0][0] == '\0') {
 		/*
 		 * Allows to not use all possible restrictions (e.g. use
-- 
2.34.1