1 files changed, 25 insertions, 13 deletions

diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index 360bebd1ee3f..f577f7abed54 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -848,6 +848,12 @@ static int ntfs_read_locked_inode(struct inode *vi)
 					a->data.resident.value_offset),
 					le32_to_cpu(
 					a->data.resident.value_length));
+			/* A resident list is not validated on load; check it now. */
+			if (!ntfs_attr_list_is_valid(ni->attr_list,
+						     ni->attr_list_size)) {
+				ntfs_error(vi->i_sb, "Corrupt attribute list.");
+				goto unm_err_out;
+			}
 		}
 	}
 skip_attr_list_load:
@@ -890,7 +896,6 @@ skip_attr_list_load:
 	 */
 	if (S_ISDIR(vi->i_mode)) {
 		struct index_root *ir;
-		u8 *ir_end, *index_end;
 
 view_index_meta:
 		/* It is a directory, find index root attribute. */
@@ -940,10 +945,9 @@ view_index_meta:
 		}
 		ir = (struct index_root *)((u8 *)a +
 				le16_to_cpu(a->data.resident.value_offset));
-		ir_end = (u8 *)ir + le32_to_cpu(a->data.resident.value_length);
-		index_end = (u8 *)&ir->index +
-				le32_to_cpu(ir->index.index_length);
-		if (index_end > ir_end) {
+		if (ntfs_index_root_inconsistent(ni->vol, a, ir, ni->mft_no) ||
+		    ntfs_index_entries_inconsistent(ni->vol, &ir->index,
+						    ir->collation_rule, ni->mft_no)) {
 			ntfs_error(vi->i_sb, "Directory index is corrupt.");
 			goto unm_err_out;
 		}
@@ -1180,6 +1184,15 @@ no_data_attr_special_case:
 		vi->i_flags |= S_IMMUTABLE;
 
 	/*
+	 * System files such as $Bitmap and $MFT are maintained by the driver
+	 * itself, and writing them from userspace corrupts the volume.
+	 * Always make them immutable regardless of the sys_immutable option.
+	 * Directories are skipped so the root and $Extend stay usable.
+	 */
+	if (ni->mft_no < FILE_first_user && S_ISREG(vi->i_mode))
+		vi->i_flags |= S_IMMUTABLE;
+
+	/*
 	 * The number of 512-byte blocks used on disk (for stat). This is in so
 	 * far inaccurate as it doesn't account for any named streams or other
 	 * special non-resident attributes, but that is how Windows works, too,
@@ -1195,6 +1208,9 @@ no_data_attr_special_case:
 	else
 		vi->i_blocks = ni->allocated_size >> 9;
 
+	if (S_ISLNK(vi->i_mode) && ni->target)
+		vi->i_size = strlen(ni->target);
+
 	ntfs_debug("Done.");
 	return 0;
 unm_err_out:
@@ -1483,7 +1499,6 @@ static int ntfs_read_locked_index_inode(struct inode *base_vi, struct inode *vi)
 	struct attr_record *a;
 	struct ntfs_attr_search_ctx *ctx;
 	struct index_root *ir;
-	u8 *ir_end, *index_end;
 	int err = 0;
 
 	ntfs_debug("Entering for i_ino 0x%llx.", ni->mft_no);
@@ -1534,9 +1549,9 @@ static int ntfs_read_locked_index_inode(struct inode *base_vi, struct inode *vi)
 	}
 
 	ir = (struct index_root *)((u8 *)a + le16_to_cpu(a->data.resident.value_offset));
-	ir_end = (u8 *)ir + le32_to_cpu(a->data.resident.value_length);
-	index_end = (u8 *)&ir->index + le32_to_cpu(ir->index.index_length);
-	if (index_end > ir_end) {
+	if (ntfs_index_root_inconsistent(vol, a, ir, ni->mft_no) ||
+	    ntfs_index_entries_inconsistent(vol, &ir->index,
+					    ir->collation_rule, ni->mft_no)) {
 		ntfs_error(vi->i_sb, "Index is corrupt.");
 		goto unm_err_out;
 	}
@@ -1994,10 +2009,7 @@ int ntfs_read_inode_mount(struct inode *vi)
 			/* Catch the end of the attribute list. */
 			if ((u8 *)al_entry == al_end)
 				goto em_put_err_out;
-			if (!al_entry->length)
-				goto em_put_err_out;
-			if ((u8 *)al_entry + 6 > al_end ||
-			    (u8 *)al_entry + le16_to_cpu(al_entry->length) > al_end)
+			if (!ntfs_attr_list_entry_is_valid(al_entry, al_end))
 				goto em_put_err_out;
 			next_al_entry = (struct attr_list_entry *)((u8 *)al_entry +
 					le16_to_cpu(al_entry->length));