From: Jan Kara <jack@xxxxxxx> commit e96a1866b40570b5950cda8602c2819189c62a48 upstream. When isofs image is suitably corrupted isofs_read_inode() can read data beyond the end of buffer. Sanity-check the directory entry length before using it. Reported-and-tested-by: syzbot+6fc7fb214625d82af7d1@xxxxxxxxxxxxxxxxxxxxxxxxx CC: stable@xxxxxxxxxxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/isofs/inode.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -1321,6 +1321,8 @@ static int isofs_read_inode(struct inode de = (struct iso_directory_record *) (bh->b_data + offset); de_len = *(unsigned char *) de; + if (de_len < sizeof(struct iso_directory_record)) + goto fail; if (offset + de_len > bufsize) { int frag1 = bufsize - offset;