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From: Timur Tabi <ttabi@nvidia.com>
To: "sunliming@linux.dev" <sunliming@linux.dev>,
	"dakr@kernel.org" <dakr@kernel.org>
Cc: "dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"nouveau@lists.freedesktop.org" <nouveau@lists.freedesktop.org>,
	"maarten.lankhorst@linux.intel.com"
	<maarten.lankhorst@linux.intel.com>,
	"mripard@kernel.org" <mripard@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"simona@ffwll.ch" <simona@ffwll.ch>,
	"sunliming@kylinos.cn" <sunliming@kylinos.cn>
Subject: Re: [PATCH] drm/nouveau/gsp:  Fix possible NULL pointer dereference warning in r535_dmac_alloc
Date: Sat, 18 Apr 2026 17:24:22 +0000	[thread overview]
Message-ID: <abb12ec2c8d72d6a369ef7b29d0453736a07f90c.camel@nvidia.com> (raw)
In-Reply-To: <DHW9RZVWDN6Y.2G2RKSJMF5ESB@kernel.org>

On Sat, 2026-04-18 at 14:12 +0200, Danilo Krummrich wrote:
> Are we sure that this can ever return NULL in the first place? I know that
> nvkm_gsp_rm_alloc_get() internally checks for IS_ERR_OR_NULL(), but I couldn't
> find anything within the callchain that would actually return NULL.
> 
> That said, I think IS_ERR_OR_NULL() checks are misleading.

I posted a patch a couple months ago that cleans up an IS_ERR check, but it was never picked up:

https://lore.freedesktop.org/nouveau/20260103000756.1002890-1-ttabi@nvidia.com/T/#u

I'm quite certain that there are other similar issues in Nouveau w.r.t. IS_ERR_OR_NULL.

I think an audit of the Nouveau error paths is in order.  I suspect that Ben's big refactors
over the past year have resulted in some invalid error paths.


  reply	other threads:[~2026-04-18 17:24 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-18  7:14 [PATCH] drm/nouveau/gsp: Fix possible NULL pointer dereference warning in r535_dmac_alloc sunliming
2026-04-18 12:12 ` Danilo Krummrich
2026-04-18 17:24   ` Timur Tabi [this message]
2026-04-18 17:35     ` Danilo Krummrich
2026-04-18 17:44       ` Timur Tabi
2026-04-18 20:43         ` Danilo Krummrich

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