[PATCH 5.19 523/717] cifs: return correct error in ->calc_signature()

Greg Kroah-Hartman
2022-10-22T08:46:25Z

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