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=1793214366; b=jV2xBDlCNzEagDXbDm/Uc02dupXdhwOD+Wp2VpOczFxGxeDR0WBhjnnUNUoIWmg+Ftby bltcb5TMHWwFkf3zJQnYZcLdLaSEhyJZoLWszlctYFINWBs4tgNftQ+cShsIcwxKPu9Kt vyyyBR3LXPbybWCy/YDuoDipB52M/hX2Jg/rmBDSvCMRKq8WlcudRIAOdPjAqRX4veqYO IRGQPQn13WMYdFRSRfOaJ/x7AmCbckA3aCJuXW/iUdkkrOfQ6W9YymOI/oKM5aAxB2rcB schZDUkO9xcfWlRgMu3v1e7i9n1M9rhk/R+73dFn/LAKquEQwNjYrveqpOr6xDt//2g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793214366; 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=b04mQX3BKZGepUvwrsB5es36HbJXnKNlqKlyZCG2VD4=; b=1537gmgxLCAfae2QSd1mB/po+6r9uWcECxx4fTtMhamSPe1rZaphKy8hVfkGIPHFnSaj +3dvW070cAthPv6NpoisvlFGfnYxnnQYqIbFJ5AelSR0/UZBIJp3vWhS4PApX+VqjSTGn 8V7rN7KmLsIfdGk4v89gc087IcAXMLwSTD1tgmUX/dkwd4jZNZZJvo+cOFmhKOzgz/gaZ 8ZBLWqXOnLfBSix/5PggFlQnWI8wlpkQJ8IaRzDwNeuklxWOsAlInho9RX8ueyMqVb8KU I/liOQbz48hzWrnzxhGp/XBDC89Xlb1j5w04R0yHwipKwaNLAXSKsEeX6fF3xpiLCCw== 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=O7atEqPP; 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 01A5860A2639; Wed, 28 Oct 2026 19:06:05 +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=O7atEqPP Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20EDE1F01825; Wed, 28 Oct 2026 19:06:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793214365; bh=b04mQX3BKZGepUvwrsB5es36HbJXnKNlqKlyZCG2VD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=O7atEqPPpsqxV21x1FgWfKsv+XfDmj3Ws0RGiNyel1PZ4FkrjN8sFo4q6+b6XvYAx eLlX6IkisSXPhnbpJZ9xF4EW3501AHYSJplo0Kupt/ICtVWeTlAbooA/5YJJqIjbd4 pN9n1yRs5vPzwFKPj6R4t+DUfE/eOdowePds3K3E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mario Limonciello , Siyang Liu , Roman Li , Alex Hung , Daniel Wheeler , Alex Deucher , Sasha Levin Subject: [PATCH 6.1 0833/1887] drm/amd/display: fix a Null pointer dereference vulnerability Date: Wed, 28 Oct 2026 17:48:49 +0100 Message-ID: <20261028170518.381515466@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: Siyang Liu [ Upstream commit 1bcf63a44381691d6192872801f830ce3250e367 ] [Why] A null pointer dereference vulnerability exists in the AMD display driver's (DC module) cleanup function dc_destruct(). When display control context (dc->ctx) construction fails (due to memory allocation failure), this pointer remains NULL. During subsequent error handling when dc_destruct() is called, there's no NULL check before dereferencing the perf_trace member (dc->ctx->perf_trace), causing a kernel null pointer dereference crash. [How] Check if dc->ctx is non-NULL before dereferencing. Link: https://lore.kernel.org/r/tencent_54FF4252EDFB6533090A491A25EEF3EDBF06@qq.com Co-developed-by: Mario Limonciello Signed-off-by: Mario Limonciello (Updated commit text and removed unnecessary error message) Signed-off-by: Siyang Liu Signed-off-by: Roman Li Reviewed-by: Alex Hung Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 9dd8e2ba268c636c240a918e0a31e6feaee19404) Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/core/dc.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c index 7594aaf79a101..cfcd4ed1666d0 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -831,16 +831,18 @@ static void dc_destruct(struct dc *dc) dc_destroy_resource_pool(dc); - if (dc->ctx->gpio_service) - dal_gpio_service_destroy(&dc->ctx->gpio_service); + if (dc->ctx) { + if (dc->ctx->gpio_service) + dal_gpio_service_destroy(&dc->ctx->gpio_service); - if (dc->ctx->created_bios) - dal_bios_parser_destroy(&dc->ctx->dc_bios); + if (dc->ctx->created_bios) + dal_bios_parser_destroy(&dc->ctx->dc_bios); - dc_perf_trace_destroy(&dc->ctx->perf_trace); + dc_perf_trace_destroy(&dc->ctx->perf_trace); - kfree(dc->ctx); - dc->ctx = NULL; + kfree(dc->ctx); + dc->ctx = NULL; + } kfree(dc->bw_vbios); dc->bw_vbios = NULL; -- 2.53.0