From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F79925BF1C for ; Thu, 26 Jun 2025 09:21:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750929708; cv=none; b=gsQ9Ulb5cuz539/q+cIoh23kUO0xRfdNjL310U+2utYtuw+1Cij7oc+7PI4NkRswOTv5BEQowWnqPfVNz6ltIpO0RYDRMlG2d2pU7aDo3kWVcqbW0GVw8Ji811nO2a9oTfcwojp5GCCvmJqZ03speUc/Y8esM5fmYrlHTGCPdv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750929708; c=relaxed/simple; bh=TDgaHxV73A15VcYZvTJnOtCN8fl/sdcXVVdEId4/O5Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=We1XV1YLXmcD9v2hqlcCVXqWhfYpEwpGJveqKqNlHaV6wJt00MeuEjtDUw0tWQhR6+/MxFP1bQyq/0UOPBwgW75ZmKdC242qyY/T3u58opTQ6AE1cghA2Ro/x2sb1Mf69VhZeSj2+YyjKEip0pemWHvzNIb8l2oZb1CMnM0iBuU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=RfqBaS3V; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RfqBaS3V" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750929705; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=V1RpWIxhpIhaG+dP+Aru0m/IoAlqoaj7YUbbsozIeE8=; b=RfqBaS3Vz0PmBObxqef6nt0bdUOo3VWN488U3OprkQUHPHFBxxRP/Baq8G5aJjXQ/zAedm +Qk4GacT95FXB/J7G+gN8nTDIUrejT9d87oEEaUGoOilKTmh20bklp4WjTrjjFDmqC5OMD Uk+8kEHkDP8hXeot58fi/rsBtASMez0= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-62-gJCYP9X6P8OADV37SfRxmg-1; Thu, 26 Jun 2025 05:21:43 -0400 X-MC-Unique: gJCYP9X6P8OADV37SfRxmg-1 X-Mimecast-MFC-AGG-ID: gJCYP9X6P8OADV37SfRxmg_1750929702 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-3a50049f8eeso346303f8f.3 for ; Thu, 26 Jun 2025 02:21:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750929702; x=1751534502; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=V1RpWIxhpIhaG+dP+Aru0m/IoAlqoaj7YUbbsozIeE8=; b=VHlHq69J659D/BGB4ssxFs0378hP8U6siMDzWOe5X3x4/juWx0l56I4CMzK0Eoa+Z8 rsprnNCdj51rUqXwKuCgyR+8/1Asho77H2M9KwaRdWykvz99oCw695luj8nUH7iWDyyl VRSu7m+BNn4oqmI6RVhoTFFVX2I+dwIahRHKlq7MACAGy5gohmAWPUqSTi+uLi82RDlx QqPhsVsr1RzxECGjxToGkxpTT606ieXvrjrRTYUigW/9wW6TcUG895oHdHKJOaRMOejs dO15hC2ItGUXszukNWqHtaAcSrvASxMa8GrWinUAqNCQKF1i3crcG4n/iWJUK1IpTPGm J50w== X-Forwarded-Encrypted: i=1; AJvYcCUaH7DoDw/GD5SMots3698E8ra82yEneIrJa7K0aaeDSVoKzsB/lgiP49U0xoAGvhK9wCioP7W1HFBanZI=@vger.kernel.org X-Gm-Message-State: AOJu0Ywj169rla2hDaPUaGfYLlsulm4LMTa7/eBDi4R1LVY6A0R+7Um4 +3Hz+g5KrPlBAFqcNZO4KPC3K2s/IDqSO9NVDbuBPI9RzT340xJvjDUU4r4ZrJV6FAJ4w+NlHC6 FDs3OiLqEKCoOxklhD3AHaXXvKL3c73+VYNmLDXFhhmHtHDXNniCeImOCHCIT8sumyA== X-Gm-Gg: ASbGncsAPx4P8uKk6cnQ/EWrqS7BKi8BoCyMXKHBQ1OhqD3JKVmTi38S0HodykchKAJ xnHdqSSSPFp7zaRyfnmyWHpnP8K4y5tjphLunrR84U4WHiiHgOw09YOTu4kuJH1RoLQmzVpAR1Z YVNsEBecgA3zmQy+7lpIhtDAI5zSdu7RCoWFZrfobM89WRmM6rRDrsR5OYhCr1OO9cNtPDIpGff c/9yewNn5RX7We86VJyoFUEI9H59Js26Lqjk98Ife4OK73rTUYXCOYOTJErVw7o+MSRr90urYZd SUoIePyXXAyFlLR9btCw2urEepN8An00Kl+dB8PFIYa2d7H1GwYEXYaZ+LG334KrZYcZew== X-Received: by 2002:a05:6000:2c0f:b0:391:3aaf:1d5f with SMTP id ffacd0b85a97d-3a6ed6746a1mr5495715f8f.52.1750929702301; Thu, 26 Jun 2025 02:21:42 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGQH908ptIl4XWG9VAtNNzn4GS6AhbkLtgnZXZlatl+hDbFHITtgt5W1+goG/gGONisVH6vpA== X-Received: by 2002:a05:6000:2c0f:b0:391:3aaf:1d5f with SMTP id ffacd0b85a97d-3a6ed6746a1mr5495688f8f.52.1750929701873; Thu, 26 Jun 2025 02:21:41 -0700 (PDT) Received: from ?IPV6:2a0d:3344:244f:bd10:2bd0:124a:622c:badb? ([2a0d:3344:244f:bd10:2bd0:124a:622c:badb]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a6e805ed03sm7021421f8f.33.2025.06.26.02.21.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Jun 2025 02:21:41 -0700 (PDT) Message-ID: <87a7f8a6-71b1-4b90-abc7-0a680f2a99cf@redhat.com> Date: Thu, 26 Jun 2025 11:21:39 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] net: usb: usbnet: fix use-after-free in race on workqueue To: "Peter GJ. Park" , Oliver Neukum , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250625-usbnet-uaf-fix-v1-1-421eb05ae6ea@samsung.com> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20250625-usbnet-uaf-fix-v1-1-421eb05ae6ea@samsung.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/25/25 11:33 AM, Peter GJ. Park wrote: > When usbnet_disconnect() queued while usbnet_probe() processing, > it results to free_netdev before kevent gets to run on workqueue, > thus workqueue does assign_work() with referencing freeed memory address. > > For graceful disconnect and to prevent use-after-free of netdev pointer, > the fix adds canceling work and timer those are placed by usbnet_probe() > > Signed-off-by: Peter GJ. Park You should include a suitable fixes tag, and you should have specified the target tree ('net' in this case) in the prefix subjext > --- > drivers/net/usb/usbnet.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c > index c04e715a4c2ade3bc5587b0df71643a25cf88c55..3c5d9ba7fa6660273137c80106746103f84f5a37 100644 > --- a/drivers/net/usb/usbnet.c > +++ b/drivers/net/usb/usbnet.c > @@ -1660,6 +1660,9 @@ void usbnet_disconnect (struct usb_interface *intf) > usb_free_urb(dev->interrupt); > kfree(dev->padding_pkt); > > + timer_delete_sync(&dev->delay); > + tasklet_kill(&dev->bh); > + cancel_work_sync(&dev->kevent); > free_netdev(net); This happens after unregister_netdev(), which calls usbnet_stop() that already performs the above cleanup. How the race is supposed to take place? /P