Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Ronnie Sahlberg <lsahlber@redhat.com>,
        Enzo Matsumiya <ematsumiya@suse.de>,
        Steve French <stfrench@microsoft.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.19 523/717] cifs: return correct error in ->calc_signature()
Date:   Sat, 22 Oct 2022 09:26:42 +0200
Message-Id: <20221022072521.442957149@linuxfoundation.org>
In-Reply-To: <20221022072415.034382448@linuxfoundation.org>
References: <20221022072415.034382448@linuxfoundation.org>
User-Agent: quilt/0.67
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Enzo Matsumiya <ematsumiya@suse.de>

[ Upstream commit 09a1f9a168ae1f69f701689429871793174417d2 ]

If an error happens while getting the key or session in the
->calc_signature implementations, 0 (success) is returned. Fix it by
returning a proper error code.

Since it seems to be highly unlikely to happen wrap the rc check in
unlikely() too.

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Fixes: 32811d242ff6 ("cifs: Start using per session key for smb2/3 for signature generation")
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/cifs/smb2transport.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 55e79f6ee78d..334d8471346f 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -225,9 +225,9 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 	struct smb_rqst drqst;
 
 	ses = smb2_find_smb_ses(server, le64_to_cpu(shdr->SessionId));
-	if (!ses) {
+	if (unlikely(!ses)) {
 		cifs_server_dbg(VFS, "%s: Could not find session\n", __func__);
-		return 0;
+		return -ENOENT;
 	}
 
 	memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
@@ -557,8 +557,10 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 	u8 key[SMB3_SIGN_KEY_SIZE];
 
 	rc = smb2_get_sign_key(le64_to_cpu(shdr->SessionId), server, key);
-	if (rc)
-		return 0;
+	if (unlikely(rc)) {
+		cifs_server_dbg(VFS, "%s: Could not get signing key\n", __func__);
+		return rc;
+	}
 
 	if (allocate_crypto) {
 		rc = cifs_alloc_hash("cmac(aes)", &hash, &sdesc);
-- 
2.35.1