tty: fix memory leak in vc_deallocate

commit 211b4d42b70f1c1660feaa968dac0efc2a96ac4d upstream.

syzbot reported memory leak in tty/vt.
The problem was in VT_DISALLOCATE ioctl cmd.
After allocating unimap with PIO_UNIMAP it wasn't
freed via VT_DISALLOCATE, but vc_cons[currcons].d was
zeroed.

Reported-by: syzbot+bcc922b19ccc64240b42@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210327214443.21548-1-paskripkin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pavel Skripkin 2021-03-28 00:44:43 +03:00 committed by Greg Kroah-Hartman
parent 25e9c2c117
commit b1c953dc85

View File

@ -1382,6 +1382,7 @@ struct vc_data *vc_deallocate(unsigned int currcons)
atomic_notifier_call_chain(&vt_notifier_list, VT_DEALLOCATE, &param);
vcs_remove_sysfs(currcons);
visual_deinit(vc);
con_free_unimap(vc);
put_pid(vc->vt_pid);
vc_uniscr_set(vc, NULL);
kfree(vc->vc_screenbuf);