From: Nick Hainke <vincent@systemli.org>
Date: Mon, 30 Aug 2021 20:37:10 +0000 (+0200)
Subject: trace: fix potential use-after-free occurence
X-Git-Url: http://git.openwrt.org/ubox.git?a=commitdiff_plain;h=96d8bf2c7b6773636efb8b175993e5d17ff7d0bf;p=project%2Fprocd.git

trace: fix potential use-after-free occurence

char* tmp is used in the fprintf function altough it is already freed.

Fixes: e5b38fd1 ("trace: free memory allocated by blobmsg_format_json_indent()")

Signed-off-by: Nick Hainke <vincent@systemli.org>
---

diff --git a/trace/trace.c b/trace/trace.c
index 87a98a6..40cf3df 100644
--- a/trace/trace.c
+++ b/trace/trace.c
@@ -166,8 +166,8 @@ static void print_syscalls(int policy, const char *json)
 			if (!tmp)
 				return;
 
-			free(tmp);
 			fprintf(fp, "%s\n", tmp);
+			free(tmp);
 			fclose(fp);
 			ULOG_INFO("saving syscall trace to %s\n", json);
 		} else {