Patch "ntfs3: Add bounds checking to mi_enum_attr()" has been added to the 6.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    ntfs3: Add bounds checking to mi_enum_attr()

to the 6.11-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:
     ntfs3-add-bounds-checking-to-mi_enum_attr.patch
and it can be found in the queue-6.11 subdirectory.

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



commit 061fbdaa3aa9c6fa798d067e45ddeb39f914e571
Author: lei lu <llfamsec@xxxxxxxxx>
Date:   Fri Aug 23 21:39:44 2024 +0800

    ntfs3: Add bounds checking to mi_enum_attr()
    
    [ Upstream commit 556bdf27c2dd5c74a9caacbe524b943a6cd42d99 ]
    
    Added bounds checking to make sure that every attr don't stray beyond
    valid memory region.
    
    Signed-off-by: lei lu <llfamsec@xxxxxxxxx>
    Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c
index 6c76503edc200..2a375247b3c09 100644
--- a/fs/ntfs3/record.c
+++ b/fs/ntfs3/record.c
@@ -223,28 +223,19 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 		prev_type = 0;
 		attr = Add2Ptr(rec, off);
 	} else {
-		/* Check if input attr inside record. */
+		/*
+		 * We don't need to check previous attr here. There is
+		 * a bounds checking in the previous round.
+		 */
 		off = PtrOffset(rec, attr);
-		if (off >= used)
-			return NULL;
 
 		asize = le32_to_cpu(attr->size);
-		if (asize < SIZEOF_RESIDENT) {
-			/* Impossible 'cause we should not return such attribute. */
-			return NULL;
-		}
-
-		/* Overflow check. */
-		if (off + asize < off)
-			return NULL;
 
 		prev_type = le32_to_cpu(attr->type);
 		attr = Add2Ptr(attr, asize);
 		off += asize;
 	}
 
-	asize = le32_to_cpu(attr->size);
-
 	/* Can we use the first field (attr->type). */
 	if (off + 8 > used) {
 		static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
@@ -265,6 +256,12 @@ struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
 	if (t32 < prev_type)
 		return NULL;
 
+	asize = le32_to_cpu(attr->size);
+	if (asize < SIZEOF_RESIDENT) {
+		/* Impossible 'cause we should not return such attribute. */
+		return NULL;
+	}
+
 	/* Check overflow and boundary. */
 	if (off + asize < off || off + asize > used)
 		return NULL;