This is a note to let you know that I've just added the patch titled
net: hso: fix NULL-deref on disconnect regression
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-hso-fix-null-deref-on-disconnect-regression.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2ad5692db72874f02b9ad551d26345437ea4f7f3 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@xxxxxxxxxx>
Date: Mon, 26 Apr 2021 10:11:49 +0200
Subject: net: hso: fix NULL-deref on disconnect regression
From: Johan Hovold <johan@xxxxxxxxxx>
commit 2ad5692db72874f02b9ad551d26345437ea4f7f3 upstream.
Commit 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device
unregistration") fixed the racy minor allocation reported by syzbot, but
introduced an unconditional NULL-pointer dereference on every disconnect
instead.
Specifically, the serial device table must no longer be accessed after
the minor has been released by hso_serial_tty_unregister().
Fixes: 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Anirudh Rayabharam <mail@xxxxxxxxxxxxx>
Reported-by: Leonardo Antoniazzi <leoanto@xxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Reviewed-by: Anirudh Rayabharam <mail@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/usb/hso.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -3131,7 +3131,7 @@ static void hso_free_interface(struct us
cancel_work_sync(&serial_table[i]->async_put_intf);
cancel_work_sync(&serial_table[i]->async_get_intf);
hso_serial_tty_unregister(serial);
- kref_put(&serial_table[i]->ref, hso_serial_ref_free);
+ kref_put(&serial->parent->ref, hso_serial_ref_free);
}
}
Patches currently in stable-queue which might be from johan@xxxxxxxxxx are
queue-4.4/net-hso-fix-null-deref-on-disconnect-regression.patch
