From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E40C9221F2F; Wed, 20 May 2026 16:40:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779295223; cv=none; b=p9laQ7E+pzcS6VE6dJGZqPY2cAKT+ig/oV8lvEfhv0HCleqgtPRicvmut0x+IOiXICSlfDyl+XSA+Cmsbfh4PMqiP21tA3L05dnBG9CaD6T6s01MWqLF+EijszJ9meKw6FfuNhp7wzzg1CfrfIYxIwigPdRF9B1WK7O5alpzlF4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779295223; c=relaxed/simple; bh=WV0QRIl1cFvpi6pdqaNkaBW4EarKKTsBQHzCdJFQLzI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=P/77RtsPYQ+EJL2EDn9Z8WPPbg5VxBrsF2BPX2npxGbsAn/TJerXcRvt02ijEnuP87silRAS+YwA4Sd9346VfWY9CvA12ZVIT3DzrjptzdtD3sRpXWlfYGujLBXHsi8VI4mfWzGIa3lVR3adszOHZ7Q/DLrGaIOnE6WiP4O8XMk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=I4u7u8iH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="I4u7u8iH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D03C1F000E9; Wed, 20 May 2026 16:40:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779295221; bh=NHaI3Kh4NrVrqOHO3ot8vr3L1uoPglVoffT0soSddpU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=I4u7u8iHUZU7k8YOQSuONmRqRS3vTco9KBbFmwJ1LZX7NutIC4GQFsGNGDVF7wPR/ NO40lWjKmiaceAs34wleKd287R/0qh0U8Jsfywcvb23o2y7e7zaOfELUgPvRiyEMnQ 93LvIslPJfLEv0qirLIGMUtRq7YYcuB+NqmN/Tjo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Roman Li , Alex Hung , Tom Chung , Dan Carpenter , Aurabindo Pillai , Srinivasan Shanmugam , Alex Deucher , Sasha Levin Subject: [PATCH 7.0 0336/1146] drm/amd/display: Avoid NULL dereference in dc_dmub_srv error paths Date: Wed, 20 May 2026 18:09:46 +0200 Message-ID: <20260520162155.805579497@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162148.390695140@linuxfoundation.org> References: <20260520162148.390695140@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Srinivasan Shanmugam [ Upstream commit 4ae3e16f4b3bf64140f773629b765d605ee079a9 ] In dc_dmub_srv_log_diagnostic_data() and dc_dmub_srv_enable_dpia_trace(). Both functions check: if (!dc_dmub_srv || !dc_dmub_srv->dmub) and then call DC_LOG_ERROR() inside that block. DC_LOG_ERROR() uses dc_dmub_srv->ctx internally. So if dc_dmub_srv is NULL, the logging itself can dereference a NULL pointer and cause a crash. Fix this by splitting the checks. First check if dc_dmub_srv is NULL and return immediately. Then check dc_dmub_srv->dmub and log the error only when dc_dmub_srv is valid. Fixes the below: ../display/dc/dc_dmub_srv.c:962 dc_dmub_srv_log_diagnostic_data() error: we previously assumed 'dc_dmub_srv' could be null (see line 961) ../display/dc/dc_dmub_srv.c:1167 dc_dmub_srv_enable_dpia_trace() error: we previously assumed 'dc_dmub_srv' could be null (see line 1166) Fixes: 2631ac1ac328 ("drm/amd/display: add DMUB registers to crash dump diagnostic data.") Fixes: 71ba6b577a35 ("drm/amd/display: Add interface to enable DPIA trace") Cc: Roman Li Cc: Alex Hung Cc: Tom Chung Cc: Dan Carpenter Cc: Aurabindo Pillai Signed-off-by: Srinivasan Shanmugam Reviewed-by: Alex Hung Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c index b15360bcdacf7..b3cedaa596c02 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c +++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c @@ -958,7 +958,10 @@ void dc_dmub_srv_log_diagnostic_data(struct dc_dmub_srv *dc_dmub_srv) { uint32_t i; - if (!dc_dmub_srv || !dc_dmub_srv->dmub) { + if (!dc_dmub_srv) + return; + + if (!dc_dmub_srv->dmub) { DC_LOG_ERROR("%s: invalid parameters.", __func__); return; } @@ -1163,7 +1166,10 @@ void dc_dmub_srv_enable_dpia_trace(const struct dc *dc) { struct dc_dmub_srv *dc_dmub_srv = dc->ctx->dmub_srv; - if (!dc_dmub_srv || !dc_dmub_srv->dmub) { + if (!dc_dmub_srv) + return; + + if (!dc_dmub_srv->dmub) { DC_LOG_ERROR("%s: invalid parameters.", __func__); return; } -- 2.53.0