A carefully crafted squashfs filesystem can exhibit an extremly large inode size and overflow the calculation in sqfs_inode_size(). As a consequence, the squashfs driver will read from wrong locations.
Fix by using __builtin_add_overflow() to detect the overflow.
Signed-off-by: Richard Weinberger richard@nod.at --- fs/squashfs/sqfs_inode.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/squashfs/sqfs_inode.c b/fs/squashfs/sqfs_inode.c index d25cfb53e7..bb3ccd37e3 100644 --- a/fs/squashfs/sqfs_inode.c +++ b/fs/squashfs/sqfs_inode.c @@ -78,11 +78,16 @@ int sqfs_inode_size(struct squashfs_base_inode *inode, u32 blk_size)
case SQFS_SYMLINK_TYPE: case SQFS_LSYMLINK_TYPE: { + int size; + struct squashfs_symlink_inode *symlink = (struct squashfs_symlink_inode *)inode;
- return sizeof(*symlink) + - get_unaligned_le32(&symlink->symlink_size); + if (__builtin_add_overflow(sizeof(*symlink), + get_unaligned_le32(&symlink->symlink_size), &size)) + return -EINVAL; + + return size; }
case SQFS_BLKDEV_TYPE: