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 CC504BA49 for ; Tue, 7 Mar 2023 18:55:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4858AC433EF; Tue, 7 Mar 2023 18:55:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678215322; bh=AGW/09WFM/k8GGWG5/uVGrdm+v3aJ6d6UTf+CmUepmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ix48IOGvu+S8yiXrKT0ZQMXgpaCoFnrtsz5YIreZCvUueGwzlIShpE0bfR8QyGZup 9/JT/P4OIpmtDCXsCds9RA6ok/Cfozhm3LTkD3cb+VwBB9OFqu5ZxXcd6t8Rtsxacg RRCFlmfzjqd1TqsDxq4vk+g/Gj2jfeVYK4tlF8qI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marijn Suijten , Dmitry Baryshkov , Sasha Levin Subject: [PATCH 5.15 192/567] drm/msm/dpu: Disallow unallocated resources to be returned Date: Tue, 7 Mar 2023 17:58:48 +0100 Message-Id: <20230307165914.263425068@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307165905.838066027@linuxfoundation.org> References: <20230307165905.838066027@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Marijn Suijten [ Upstream commit abc40122d9a69f56c04efb5a7485795f5ac799d1 ] In the event that the topology requests resources that have not been created by the system (because they are typically not represented in dpu_mdss_cfg ^1), the resource(s) in global_state (in this case DSC blocks, until their allocation/assignment is being sanity-checked in "drm/msm/dpu: Reject topologies for which no DSC blocks are available") remain NULL but will still be returned out of dpu_rm_get_assigned_resources, where the caller expects to get an array containing num_blks valid pointers (but instead gets these NULLs). To prevent this from happening, where null-pointer dereferences typically result in a hard-to-debug platform lockup, num_blks shouldn't increase past NULL blocks and will print an error and break instead. After all, max_blks represents the static size of the maximum number of blocks whereas the actual amount varies per platform. ^1: which can happen after a git rebase ended up moving additions to _dpu_cfg to a different struct which has the same patch context. Fixes: bb00a452d6f7 ("drm/msm/dpu: Refactor resource manager") Signed-off-by: Marijn Suijten Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/517636/ Link: https://lore.kernel.org/r/20230109231556.344977-1-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c index 24fbaf562d418..932275b2dfe74 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c @@ -663,6 +663,11 @@ int dpu_rm_get_assigned_resources(struct dpu_rm *rm, blks_size, enc_id); break; } + if (!hw_blks[i]) { + DPU_ERROR("Allocated resource %d unavailable to assign to enc %d\n", + type, enc_id); + break; + } blks[num_blks++] = hw_blks[i]; } -- 2.39.2