From: Bart Van Assche <bvanassche@acm.org>
Date: Sun, 12 Jan 2020 00:10:42 +0000 (-0800)
Subject: blktrace: Check value of 'merge_buf' pointer before using it
X-Git-Tag: fio-3.18~12^2~5
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=c81ab051dd359a598414c04fcb010e959d2d5445;p=fio.git

blktrace: Check value of 'merge_buf' pointer before using it

This patch fixes the following Coverity complaint:

CID 183976 (#1 of 1): Dereference null return value (NULL_RETURNS)
5. dereference: Dereferencing a pointer that might be null 'merge_fp' when calling 'setvbuf'.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---

diff --git a/blktrace.c b/blktrace.c
index f7a9ae3b..2c2b5aeb 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -719,9 +719,11 @@ int merge_blktrace_iologs(struct thread_data *td)
 	/* setup output file */
 	merge_fp = fopen(td->o.merge_blktrace_file, "w");
 	merge_buf = malloc(128 * 1024);
+	if (!merge_buf)
+		goto err_out_file;
 	ret = setvbuf(merge_fp, merge_buf, _IOFBF, 128 * 1024);
 	if (ret)
-		goto err_out_file;
+		goto err_merge_buf;
 
 	/* setup input files */
 	str = ptr = strdup(td->o.read_iolog_file);
@@ -784,10 +786,11 @@ err_file:
 		fifo_free(bcs[i].fifo);
 		close(bcs[i].fd);
 	}
+err_merge_buf:
+	free(merge_buf);
 err_out_file:
 	fflush(merge_fp);
 	fclose(merge_fp);
-	free(merge_buf);
 err_param:
 	free(bcs);