From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793212558; b=FfVcFq//71blaNnAS/ybQeJEGub0g8ejN2NvRBM5cCfE68lKHHSdmU/CJ/W6WdXgUMT5 mYWR2Ft83BITZ5bzlQfeU5hOrQBPGMU8ngDXixmS0hR9uipXQi0gCEy8SSMx6X2HgdAnR ouCGoz+pPSrz0yOxxjCvoNIebR4xfGQN6Zx/aQMZWMZYfK62valcNdkyYnzneqHegu4xc 0PxyiE9epBTyg7G9s525hSzNJxsfmKV9BU6XdQ+A7/zBcpmOcPvjolgHWtxLd7mryrGf4 KZ6uemurrbh8zy+WnW1RIAQKrXQ/93Xa9m32YCr1VB2azO5Z/nbJz8R6FzzVBk25IQw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793212558; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=dOhGbcgXyX6A4GvIReYBLSA8gMSZuH5+MRJXW+TXhVM=; b=regyinFlMiBxaFZilWcGRBoXblbczqyWhR/Hlao0fRxg8ddVt3Kn+9GpjOuNh9OiWowe niri7MgO6D0Mf0ck5L/c6XsW7E2QK38e9G1tkMmmhv5tCJY2UgBYTWmjO9tYwX48Ss8J5 JFW9edbZazSzzF3A9vtpVKHy14AE5ZV+jaHjkCBBsEi/Js5KgrxeeWdKQM/8aPnu4Zx/Y waV9VtY79wWYQKgDhAcd3aRuQv8+xFxpI1AV28wLEvEKH+PZ3UgP6O4WtnxykjpmLpP4p e2tyYBDfmXSb4Sh5mwoL4VYnleZSw4fI8z8UOROa2ivq/jRZ/42IkdGeTnxB25Hx3vw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=dC7xV9nu; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5BD2D606A31A; Wed, 28 Oct 2026 18:35:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=dC7xV9nu Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0F291F01825; Wed, 28 Oct 2026 18:35:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793212558; bh=dOhGbcgXyX6A4GvIReYBLSA8gMSZuH5+MRJXW+TXhVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dC7xV9nuN3S0we1iYd5WfGjFF3Rle0ATZkhndf2mskutl5eUe5LIrKzLP9lliHeNC WVigv/wXFQUPKYIf7ouceXIYsOVRAqoNv48IpyC3/49mr84TxiNULXtufxB4O8AgXk XLR2yMUe0EFMf/gMbOKLrvchyAAVDk8uYR7B9rjo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , AngeloGioacchino Del Regno , CK Hu , Chun-Kuang Hu , Artem Dinaburg , Sasha Levin Subject: [PATCH 6.1 0194/1887] drm/mediatek: Fix potential NULL dereference in mtk_crtc_destroy() Date: Wed, 28 Oct 2026 17:38:10 +0100 Message-ID: <20261028170503.650285570@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter [ Upstream commit 4018651ba5c409034149f297d3dd3328b91561fd ] In mtk_crtc_create(), if the call to mbox_request_channel() fails then we set the "mtk_crtc->cmdq_client.chan" pointer to NULL. In that situation, we do not call cmdq_pkt_create(). During the cleanup, we need to check if the "mtk_crtc->cmdq_client.chan" is NULL first before calling cmdq_pkt_destroy(). Calling cmdq_pkt_destroy() is unnecessary if we didn't call cmdq_pkt_create() and it will result in a NULL pointer dereference. [ Backport to 6.1.y: used the older Mediatek CRTC file and helper names. ] Fixes: 7627122fd1c0 ("drm/mediatek: Add cmdq_handle in mtk_crtc") Signed-off-by: Dan Carpenter Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/dri-devel/patch/cc537bd6-837f-4c85-a37b-1a007e268310@stanley.mountain/ Signed-off-by: Chun-Kuang Hu Assisted-by: LLM Signed-off-by: Artem Dinaburg Signed-off-by: Sasha Levin --- drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c index 59b310f7327c8..8e72b3bb51eb9 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c @@ -161,9 +161,8 @@ static void mtk_drm_crtc_destroy(struct drm_crtc *crtc) mtk_mutex_put(mtk_crtc->mutex); #if IS_REACHABLE(CONFIG_MTK_CMDQ) - mtk_drm_cmdq_pkt_destroy(&mtk_crtc->cmdq_handle); - if (mtk_crtc->cmdq_client.chan) { + mtk_drm_cmdq_pkt_destroy(&mtk_crtc->cmdq_handle); mbox_free_channel(mtk_crtc->cmdq_client.chan); mtk_crtc->cmdq_client.chan = NULL; } -- 2.53.0