[PATCH] tty: fix memory leak in vc_deallocate

Pavel Skripkin
2021-03-27T21:45:58Z

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.

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reported-by: syzbot+bcc922b19ccc64240b42@syzkaller.appspotmail.com
---
drivers/tty/vt/vt.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 284b07224c55..0cc360da5426 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1381,6 +1381,7 @@ 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);
--
2.30.2