From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E806C4332F for ; Sun, 12 Nov 2023 13:31:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232477AbjKLNbm (ORCPT ); Sun, 12 Nov 2023 08:31:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232874AbjKLNat (ORCPT ); Sun, 12 Nov 2023 08:30:49 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A4CE5FC8; Sun, 12 Nov 2023 05:29:22 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5BD0C43395; Sun, 12 Nov 2023 13:29:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699795762; bh=ckoGjyC0/jwc26OxRRvzVlsmw9trxr1M39AQ/VPMYYQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iFXkIBSCFvzw76o/oq5omHADxxP18GsZOo4py3VPJyM1o4AY7xc1YRI2lrp2LyIVk 01PrSiuJVrqWPZCmBoKjzPYnHl+Q89x+aeKsEE/UoufcFlwtiDepqeQjKSbUlKLL+J iv+ehVO7kNi1eLpaFj9yXcmNsKqo2tRRLHrgdPAnKBjuvqatarzSnvCzSutDKSiI8V fqo7sWDWdxJUr+lYA7/EM7XYpQ7JbnQGtbz5v+ajUeA0ysGp+4DaXI7nSk90QxBsvf kKOIVcxNZdusLQ2GAsQ0OCVc7bKh2n9t0Mm2E3KKKfmeSkmJ9Dbczh32I5ySUNFGF5 qjSWNO6axqvJQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wayne Lin , Jun Lei , Hersen Wu , Daniel Wheeler , Alex Deucher , Sasha Levin , christian.koenig@amd.com, airlied@linux.ie, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 4.19 5/5] drm/amd/display: Avoid NULL dereference of timing generator Date: Sun, 12 Nov 2023 08:29:12 -0500 Message-ID: <20231112132913.176824-5-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231112132913.176824-1-sashal@kernel.org> References: <20231112132913.176824-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.298 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wayne Lin [ Upstream commit b1904ed480cee3f9f4036ea0e36d139cb5fee2d6 ] [Why & How] Check whether assigned timing generator is NULL or not before accessing its funcs to prevent NULL dereference. Reviewed-by: Jun Lei Acked-by: Hersen Wu Signed-off-by: Wayne Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c index fdcc8ab19bf3f..25b8a8f933821 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c @@ -281,7 +281,7 @@ uint32_t dc_stream_get_vblank_counter(const struct dc_stream_state *stream) for (i = 0; i < MAX_PIPES; i++) { struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg; - if (res_ctx->pipe_ctx[i].stream != stream) + if (res_ctx->pipe_ctx[i].stream != stream || !tg) continue; return tg->funcs->get_frame_count(tg); @@ -305,7 +305,7 @@ bool dc_stream_get_scanoutpos(const struct dc_stream_state *stream, for (i = 0; i < MAX_PIPES; i++) { struct timing_generator *tg = res_ctx->pipe_ctx[i].stream_res.tg; - if (res_ctx->pipe_ctx[i].stream != stream) + if (res_ctx->pipe_ctx[i].stream != stream || !tg) continue; tg->funcs->get_scanoutpos(tg, -- 2.42.0