ext4: always initialize the crc32c checksum driver

The extended attribute code now uses the crc32c checksum for hashing purposes, so we should just always always initialize it. We also want to prevent NULL pointer dereferences if one of the metadata checksum features is enabled after the file sytsem is originally mounted. This issue has been assigned CVE-2018-1094. https://bugzilla.kernel.org/show_bug.cgi?id=199183 https://bugzilla.redhat.com/show_bug.cgi?id=1560788 Signed-off-by: Theodore Ts'o <[email protected]> Cc: [email protected]
XGWang0 · Mar 30, 2018 · a45403b · a45403b
1 parent 8e4b5ea
commit a45403b
Showing 1 changed file with 6 additions and 9 deletions.
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
@@ -3492,15 +3492,12 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	}
 
 	/* Load the checksum driver */
-	if (ext4_has_feature_metadata_csum(sb) ||
-	    ext4_has_feature_ea_inode(sb)) {
-		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
-		if (IS_ERR(sbi->s_chksum_driver)) {
-			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
-			ret = PTR_ERR(sbi->s_chksum_driver);
-			sbi->s_chksum_driver = NULL;
-			goto failed_mount;
-		}
+	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
+	if (IS_ERR(sbi->s_chksum_driver)) {
+		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
+		ret = PTR_ERR(sbi->s_chksum_driver);
+		sbi->s_chksum_driver = NULL;
+		goto failed_mount;
 	}
 
 	/* Check superblock checksum */