Patch "smack: Retrieve transmuting information in smack_inode_getsecurity()" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    smack: Retrieve transmuting information in smack_inode_getsecurity()

to the 5.4-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:
     smack-retrieve-transmuting-information-in-smack_inod.patch
and it can be found in the queue-5.4 subdirectory.

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



commit 708921670d2baaff5f85759a605bec44700067d5
Author: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
Date:   Mon May 8 19:02:33 2023 +0200

    smack: Retrieve transmuting information in smack_inode_getsecurity()
    
    [ Upstream commit 3a3d8fce31a49363cc31880dce5e3b0617c9c38b ]
    
    Enhance smack_inode_getsecurity() to retrieve the value for
    SMACK64TRANSMUTE from the inode security blob, similarly to SMACK64.
    
    This helps to display accurate values in the situation where the security
    labels come from mount options and not from xattrs.
    
    Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
    Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b8e040460ad28..bff67bedd838f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1454,10 +1454,19 @@ static int smack_inode_getsecurity(struct inode *inode,
 	struct super_block *sbp;
 	struct inode *ip = (struct inode *)inode;
 	struct smack_known *isp;
+	struct inode_smack *ispp;
+	size_t label_len;
+	char *label = NULL;
 
-	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
+	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
 		isp = smk_of_inode(inode);
-	else {
+	} else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) {
+		ispp = smack_inode(inode);
+		if (ispp->smk_flags & SMK_INODE_TRANSMUTE)
+			label = TRANS_TRUE;
+		else
+			label = "";
+	} else {
 		/*
 		 * The rest of the Smack xattrs are only on sockets.
 		 */
@@ -1479,13 +1488,18 @@ static int smack_inode_getsecurity(struct inode *inode,
 			return -EOPNOTSUPP;
 	}
 
+	if (!label)
+		label = isp->smk_known;
+
+	label_len = strlen(label);
+
 	if (alloc) {
-		*buffer = kstrdup(isp->smk_known, GFP_KERNEL);
+		*buffer = kstrdup(label, GFP_KERNEL);
 		if (*buffer == NULL)
 			return -ENOMEM;
 	}
 
-	return strlen(isp->smk_known);
+	return label_len;
 }