From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F00D93BC687; Thu, 23 Apr 2026 11:40:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776944442; cv=none; b=Ve1ZtrYH0p46nJ+yNyuGflUrn8GPAbt8PX+zxHmB1YnxTTPZ9NosnT8+W5WZfDRQwwBPSFHXY2b7dOfGOoRTRa3ZwOhtz2xgczfuEyM+jdE/qxPAFq56C87R4INQMX2ebCCLXgQvyaMwD/OlXGN6T3GKFQhYmNxt7kmxjN6ygeY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776944442; c=relaxed/simple; bh=XWpyzthTDl8osOJZCyGUAdA1IW4nOmyc8fO7wAVzzhk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=DLqbzdys4/h6PV7JaGO7pp9QM0A9CgWE9VlHY9NaB7ub+5Yx/6z0J7oPWGKHSx9lnJXkUUv07OllLCK0sDwprI/c3ByVEXl/+AI8Y56/rP9FpRIZlaJO5NRYFRlSvcF4UoldvQfK/AGMpSGYE7IGUdk/McbmSVC2tf7+QJs+394= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A9zIJ8W5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="A9zIJ8W5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60D82C2BCAF; Thu, 23 Apr 2026 11:40:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776944441; bh=XWpyzthTDl8osOJZCyGUAdA1IW4nOmyc8fO7wAVzzhk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A9zIJ8W5rUljqWcYOM2NMB8yCRv5QyRJso61Dr+oylA1kSt3a58vGL9WIEFRWn75I bPSFsVbGzQhg9+HByVx9r2XzSY1cjq3g/jexNuy/h4HkRV34294O5bRNUa5rlLt+Eg l544Jm3OVB4hk49omkplHMkr9Lg6RM4ONxWHrD6A= Date: Thu, 23 Apr 2026 13:40:39 +0200 From: Greg Kroah-Hartman To: Timur =?iso-8859-1?Q?Krist=F3f?= Cc: Christian =?iso-8859-1?Q?K=F6nig?= , stable@vger.kernel.org, Robert Garcia , Alex Deucher , Pan Xinhui , David Airlie , Daniel Vetter , Yifan Zha , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6.1.y] drm/amdgpu: remove two invalid BUG_ON()s Message-ID: <2026042330-washhouse-amusement-db9e@gregkh> References: <20260417074010.1607496-1-rob_garcia@163.com> <6064b45a-b8de-4848-856f-383d2d06680d@amd.com> <2026042335-probation-heftiness-7399@gregkh> <4885687.vXUDI8C0e8@timur-hyperion> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4885687.vXUDI8C0e8@timur-hyperion> On Thu, Apr 23, 2026 at 01:34:42PM +0200, Timur Kristóf wrote: > On Thursday, April 23, 2026 1:22:22 PM Central European Summer Time Greg > Kroah-Hartman wrote: > > On Wed, Apr 22, 2026 at 04:11:15PM +0200, Christian König wrote: > > > Those points are certainly valid. > > > > > > I've also up-streamed a patch which completely rejects userspace > > > submissions who try to use the CE. > > > > > > The problem is that those BUG_ON() can lead to a deny of service because > > > they crash the whole kernel. > > > > > > A BUG_ON() is only justified if it prevents even worse things to happen, > > > e.g. data corruption or it would crash later on anyway just not so > > > obvious on what is wrong. > > > > > > Otherwise we should use WARN_ON(). > > > > WARN_ON() crashes the kernel as well when panic-on-warn is enabled, as > > it is in a few billion Linux systems :( > > > > As this commit is upstream, and in other stable trees, I'll apply this > > as it's not nice to have a simple way for userspace to crash the system. > > > > thanks, > > > > greg k-h > > Sounds reasonable, if you feel this improves stability. > > That being said, there are many other ways besides this one for userspace to > crash the system equally easily. Great, please fix up those as well :)