git: fb87708c51a4 - stable/12 - ssh-keygen: fix double free in error path

The branch stable/12 has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=fb87708c51a4c6c6e10e77af84f77d0a77069f77

commit fb87708c51a4c6c6e10e77af84f77d0a77069f77
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2022-10-04 20:31:39 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2022-10-07 13:22:10 +0000

    ssh-keygen: fix double free in error path
    
    From OpenSSH-portable commit 5062ad48814b, OpenBSD commit 39f35e16ba87.
    
    MFC after:      3 days
    
    (cherry picked from commit 666605ad2df3f5c1fb973dbd719ffbe3f3935c1d)
    (cherry picked from commit 02c646bb7288986912ad7bbe410636d0e257eda9)
---
 crypto/openssh/sshsig.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/crypto/openssh/sshsig.c b/crypto/openssh/sshsig.c
index 1e3b63982ba8..eb2a931e9c18 100644
--- a/crypto/openssh/sshsig.c
+++ b/crypto/openssh/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
  *
@@ -491,7 +491,7 @@ 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;
 
@@ -514,7 +514,6 @@ 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;
@@ -549,9 +548,11 @@ 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;
 }