Patch "cifs: return correct error in ->calc_signature()" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cifs: return correct error in ->calc_signature()

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cifs-return-correct-error-in-calc_signature.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit f5cb1d0d42ed22d528d84ad36b560bfa6ab5ef9c
Author: Enzo Matsumiya <ematsumiya@xxxxxxx>
Date:   Fri Sep 16 20:57:05 2022 -0300

    cifs: return correct error in ->calc_signature()
    
    [ 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@xxxxxxxxxx>
    Fixes: 32811d242ff6 ("cifs: Start using per session key for smb2/3 for signature generation")
    Signed-off-by: Enzo Matsumiya <ematsumiya@xxxxxxx>
    Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 2bf047b390a9..0f1c8dccbae8 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -220,9 +220,9 @@ 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);
@@ -541,8 +541,10 @@ 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);