From: juyin <zhuyan34@huawei.com>
Date: Wed, 30 Mar 2022 11:21:32 +0000 (+0800)
Subject: libmisc: add check fopen return value in read_random_bytes()
X-Git-Tag: 4.12~51
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a43d0b95c44b2c36025452b772b9d4b251281e3e;p=thirdparty%2Fshadow.git

libmisc: add check fopen return value in read_random_bytes()

Returns null when fopen fails. Then, using fread with a null pointer will cause a segfault.

Signed-off-by: Yan Zhu <zhuyan34@huawei.com>
---

diff --git a/libmisc/salt.c b/libmisc/salt.c
index f8ac56696..ebf162fc1 100644
--- a/libmisc/salt.c
+++ b/libmisc/salt.c
@@ -175,6 +175,9 @@ static long read_random_bytes (void)
 
 #else
 	FILE *f = fopen ("/dev/urandom", "r");
+	if (NULL == f) {
+		goto fail;
+	}
 
 	if (fread (&randval, sizeof (randval), 1, f) != 1) {
 		fclose(f);