loop: add recursion validation to LOOP_CHANGE_FD
Refactor the validation code used in LOOP_SET_FD so it is also used in LOOP_CHANGE_FD. Otherwise it is possible to construct a set of loop devices that all refer to each other. This can lead to a infinite loop in starting with "while (is_loop_device(f)) .." in loop_set_fd(). Fix this by refactoring out the validation code and using it for LOOP_CHANGE_FD as well as LOOP_SET_FD. Reported-by: syzbot+4349872271ece473a7c91190b68b4bac7c5dbc87@syzkaller.appspotmail.com Reported-by: syzbot+40bd32c4d9a3cc12a339@syzkaller.appspotmail.com Reported-by: syzbot+769c54e66f994b041be7@syzkaller.appspotmail.com Reported-by: syzbot+0a89a9ce473936c57065@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Showing
Please register or sign in to comment