From nobody Sun Feb 8 11:39:37 2026 Received: from cstnet.cn (smtp21.cstnet.cn [159.226.251.21]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0C8E1C6B4; Mon, 26 May 2025 02:38:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.21 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748227132; cv=none; b=GmbC1spWKSHMGsSeie0nJ443gvkxB8dFv7Sgd6OB/GNl8/GbsLfkvlf37S0qUH5bP2kFiTebQXY6RGK5tgTpYm7G3+e6hsg4IB7iWHf/uHV4LXcchxFJXlp4xy8rmwWZGg3Ho7oEa7QU4TkdxHRhG20ywy8HLy86n7i7EnEpdEk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748227132; c=relaxed/simple; bh=3oAnMTvt0OO/ipksasFtW6n/8Gz/YRwaYDZyeSEjbSg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=cs6V/bYMCY7BU7iqek/w1j/nBt/qMfILq5JZXjh4ofMVbohVBFocnPXtbgxLE3Uljo0Geo/Oo1dyV4fmvUt7K0hTqVUouJY/KDeswh+Fm4J83xfTc0DG05r3sR43ZPJbORaH1bWRIY5H+ZdClNHtMZPosxmvo6cPXutNnaJAL6s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from localhost.localdomain (unknown [124.16.141.245]) by APP-01 (Coremail) with SMTP id qwCowABXCNco1DNoOSgHAA--.2474S2; Mon, 26 May 2025 10:38:34 +0800 (CST) From: Wentao Liang To: harry.wentland@amd.com, sunpeng.li@amd.com, Rodrigo.Siqueira@amd.com, alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, crypto@vger.kernel.org, airlied@gmail.com, simona@ffwll.ch Cc: alex.hung@amd.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Wentao Liang , stable@vger.kernel.org Subject: [PATCH] drm/amd/display: Add null pointer check for get_first_active_display() Date: Mon, 26 May 2025 10:37:31 +0800 Message-ID: <20250526023732.325-1-vulab@iscas.ac.cn> X-Mailer: git-send-email 2.42.0.windows.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: qwCowABXCNco1DNoOSgHAA--.2474S2 X-Coremail-Antispam: 1UD129KBjvJXoW7WF15uFyrur4fAFWrZrWUurg_yoW8Wr13pw 45XFy3ury5CFnFgay8J3WkWF98Kw18ZFy3GFZ5Cwn3ua18Ar43Aa4rCr13urWUGFWUWa1S yF10gay7trWDArDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9014x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4j 6r4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628v n2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7x kEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E 67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCw CI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1x MIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIda VFxhVjvjDU0xZFpf9x0JUd-B_UUUUU= X-CM-SenderInfo: pyxotu46lvutnvoduhdfq/1tbiCRAOA2gzuBuKxQAAsj Content-Type: text/plain; charset="utf-8" The function mod_hdcp_hdcp1_enable_encryption() calls the function get_first_active_display(), but does not check its return value. The return value is a null pointer if the display list is empty. This will lead to a null pointer dereference in mod_hdcp_hdcp2_enable_encryption(). Add a null pointer check for get_first_active_display() and return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND if the function return null. Fixes: 2deade5ede56 ("drm/amd/display: Remove hdcp display state with mst f= ix") Cc: stable@vger.kernel.org # v5.8 Signed-off-by: Wentao Liang Reviewed-by: Alex Hung --- drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c b/drivers/= gpu/drm/amd/display/modules/hdcp/hdcp_psp.c index 8c137d7c032e..e58e7b93810b 100644 --- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c +++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_psp.c @@ -368,6 +368,9 @@ enum mod_hdcp_status mod_hdcp_hdcp1_enable_encryption(s= truct mod_hdcp *hdcp) struct mod_hdcp_display *display =3D get_first_active_display(hdcp); enum mod_hdcp_status status =3D MOD_HDCP_STATUS_SUCCESS; =20 + if (!display) + return MOD_HDCP_STATUS_DISPLAY_NOT_FOUND; + mutex_lock(&psp->hdcp_context.mutex); hdcp_cmd =3D (struct ta_hdcp_shared_memory *)psp->hdcp_context.context.me= m_context.shared_buf; memset(hdcp_cmd, 0, sizeof(struct ta_hdcp_shared_memory)); --=20 2.42.0.windows.2