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@xxxxxxxxxxxxxxx> --- fs/squashfs/dir.c | 7 +++++-- fs/squashfs/squashfs_fs.h | 5 ++++- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/squashfs/dir.c b/fs/squashfs/dir.c index bd7155b..d8c2d74 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])) diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h index 9e2349d..4b2beda 100644 --- a/fs/squashfs/squashfs_fs.h +++ b/fs/squashfs/squashfs_fs.h @@ -87,7 +87,7 @@ #define SQUASHFS_COMP_OPTS(flags) SQUASHFS_BIT(flags, \ SQUASHFS_COMP_OPT) -/* Max number of types and file types */ +/* Inode types including extended types */ #define SQUASHFS_DIR_TYPE 1 #define SQUASHFS_REG_TYPE 2 #define SQUASHFS_SYMLINK_TYPE 3 @@ -103,6 +103,9 @@ #define SQUASHFS_LFIFO_TYPE 13 #define SQUASHFS_LSOCKET_TYPE 14 +/* Max type value stored in directory entry */ +#define SQUASHFS_MAX_DIR_TYPE 7 + /* Xattr types */ #define SQUASHFS_XATTR_USER 0 #define SQUASHFS_XATTR_TRUSTED 1 -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
