From: djm <djm@openbsd.org>
Date: Fri, 19 Aug 2022 03:06:30 +0000 (+0000)
Subject: double free() in error path; from Eusgor via GHPR333
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=3371639182176eae5f9f0e543502cff6006006fe;p=openbsd

double free() in error path; from Eusgor via GHPR333
---

diff --git a/usr.bin/ssh/sshsig.c b/usr.bin/ssh/sshsig.c
index 56cd59a3373..bdfb3b44442 100644
--- a/usr.bin/ssh/sshsig.c
+++ b/usr.bin/ssh/sshsig.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshsig.c,v 1.29 2022/03/30 04:27:51 djm Exp $ */
+/* $OpenBSD: sshsig.c,v 1.30 2022/08/19 03:06:30 djm Exp $ */
 /*
  * Copyright (c) 2019 Google LLC
  *
@@ -489,7 +489,7 @@ hash_file(int fd, const char *hashalg, struct sshbuf **bp)
 {
 	char *hex, rbuf[8192], hash[SSH_DIGEST_MAX_LENGTH];
 	ssize_t n, total = 0;
-	struct ssh_digest_ctx *ctx;
+	struct ssh_digest_ctx *ctx = NULL;
 	int alg, oerrno, r = SSH_ERR_INTERNAL_ERROR;
 	struct sshbuf *b = NULL;
 
@@ -512,7 +512,6 @@ hash_file(int fd, const char *hashalg, struct sshbuf **bp)
 				continue;
 			oerrno = errno;
 			error_f("read: %s", strerror(errno));
-			ssh_digest_free(ctx);
 			errno = oerrno;
 			r = SSH_ERR_SYSTEM_ERROR;
 			goto out;
@@ -547,9 +546,11 @@ hash_file(int fd, const char *hashalg, struct sshbuf **bp)
 	/* success */
 	r = 0;
  out:
+	oerrno = errno;
 	sshbuf_free(b);
 	ssh_digest_free(ctx);
 	explicit_bzero(hash, sizeof(hash));
+	errno = oerrno;
 	return r;
 }