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authorPhillip Lougher <phillip@squashfs.org.uk>2013-09-04 02:58:12 +0100
committerPhillip Lougher <phillip@squashfs.org.uk>2013-09-06 04:57:54 +0100
commit9e012423869e1efbae3762b87ceab509027231c9 (patch)
treedd451cda9f1a82f6ea83c645807bb459c51b4bf8 /fs/squashfs/dir.c
parentf960cae5357d8e52b8af91e8b1621cae565dffb3 (diff)
downloadlinux-9e012423869e1efbae3762b87ceab509027231c9.tar.gz
Squashfs: add corruption check for type in squashfs_readdir()
We read the type field from disk.  This value should be sanity
checked for correctness to avoid an out of bounds access when
reading the squashfs_filetype_table array.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Diffstat (limited to 'fs/squashfs/dir.c')
-rw-r--r--fs/squashfs/dir.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/squashfs/dir.c b/fs/squashfs/dir.c
index bd7155b198a9..d8c2d747be28 100644
--- a/fs/squashfs/dir.c
+++ b/fs/squashfs/dir.c
@@ -112,8 +112,8 @@ static int squashfs_readdir(struct file *file, struct dir_context *ctx)
 	struct inode *inode = file_inode(file);
 	struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info;
 	u64 block = squashfs_i(inode)->start + msblk->directory_table;
-	int offset = squashfs_i(inode)->offset, length, type, err;
-	unsigned int inode_number, dir_count, size;
+	int offset = squashfs_i(inode)->offset, length, err;
+	unsigned int inode_number, dir_count, size, type;
 	struct squashfs_dir_header dirh;
 	struct squashfs_dir_entry *dire;
 
@@ -206,6 +206,9 @@ static int squashfs_readdir(struct file *file, struct dir_context *ctx)
 				((short) le16_to_cpu(dire->inode_number));
 			type = le16_to_cpu(dire->type);
 
+			if (type > SQUASHFS_MAX_DIR_TYPE)
+				goto failed_read;
+
 			if (!dir_emit(ctx, dire->name, size,
 					inode_number,
 					squashfs_filetype_table[type]))