* [PATCH] net: hso: fix NULL-deref on disconnect regression
@ 2021-04-26 8:11 Johan Hovold
2021-04-26 14:01 ` Anirudh Rayabharam
2021-04-26 20:00 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Johan Hovold @ 2021-04-26 8:11 UTC (permalink / raw)
To: David S. Miller, Jakub Kicinski
Cc: Greg Kroah-Hartman, linux-usb, netdev, linux-kernel,
Johan Hovold, stable, Anirudh Rayabharam, Leonardo Antoniazzi
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@vger.kernel.org
Cc: Anirudh Rayabharam <mail@anirudhrb.com>
Reported-by: Leonardo Antoniazzi <leoanto@aruba.it>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/net/usb/hso.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 9bc58e64b5b7..3ef4b2841402 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -3104,7 +3104,7 @@ static void hso_free_interface(struct usb_interface *interface)
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);
}
}
--
2.26.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] net: hso: fix NULL-deref on disconnect regression
2021-04-26 8:11 [PATCH] net: hso: fix NULL-deref on disconnect regression Johan Hovold
@ 2021-04-26 14:01 ` Anirudh Rayabharam
2021-04-26 20:00 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Anirudh Rayabharam @ 2021-04-26 14:01 UTC (permalink / raw)
To: Johan Hovold
Cc: David S. Miller, Jakub Kicinski, Greg Kroah-Hartman, linux-usb,
netdev, linux-kernel, stable, Leonardo Antoniazzi, mail
On Mon, Apr 26, 2021 at 10:11:49AM +0200, Johan Hovold wrote:
> 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@vger.kernel.org
> Cc: Anirudh Rayabharam <mail@anirudhrb.com>
> Reported-by: Leonardo Antoniazzi <leoanto@aruba.it>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
> drivers/net/usb/hso.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
> index 9bc58e64b5b7..3ef4b2841402 100644
> --- a/drivers/net/usb/hso.c
> +++ b/drivers/net/usb/hso.c
> @@ -3104,7 +3104,7 @@ static void hso_free_interface(struct usb_interface *interface)
> 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);
> }
> }
Ah, my bad. Thanks Johan for the fix!
Reviewed-by: Anirudh Rayabharam <mail@anirudhrb.com>
- Anirudh.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] net: hso: fix NULL-deref on disconnect regression
2021-04-26 8:11 [PATCH] net: hso: fix NULL-deref on disconnect regression Johan Hovold
2021-04-26 14:01 ` Anirudh Rayabharam
@ 2021-04-26 20:00 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-04-26 20:00 UTC (permalink / raw)
To: Johan Hovold
Cc: davem, kuba, gregkh, linux-usb, netdev, linux-kernel, stable,
mail, leoanto
Hello:
This patch was applied to netdev/net-next.git (refs/heads/master):
On Mon, 26 Apr 2021 10:11:49 +0200 you wrote:
> 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().
>
> [...]
Here is the summary with links:
- net: hso: fix NULL-deref on disconnect regression
https://git.kernel.org/netdev/net-next/c/2ad5692db728
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-04-26 14:01 ` Anirudh Rayabharam
2021-04-26 20:00 ` patchwork-bot+netdevbpf
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