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=1793213773; b=4P9v67ZOumxnXTHqxOpKd/XHfgpld+KZnicXSS80X1WW7ZwKU9OfiQYay2Zzs5/9ksAR B0S5bfsPzVhHHAbebu0YyeXgEAJ4jaGcKBFljH3sFtFVz8RTKTnI0x6E2WsiLZh8ATvAJ 5hXWZsU+LwR5x7AhrzGGzMQWJuWRjHgA80nzWu1P2TDMdSZS8y2A1aiDC0lLsBrefIX3g ufAjIyJNXbndnAZlMEpPgo1zY5mn4mQsXrapnjoUj1n/z7ZpN6jpYXwwHXi1nMIZOUzOu WiqUmCobg/IXn3CdLcbSS+35GVBLDTibiIXHcykEuv7/GdVwNSsGX+aoT5dZHY8pe9Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793213773; 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=51g+3I2HTKORk1mFF1gb75CkfimuaoL7jrcc4LBi0WM=; b=eYm4KB6rkFPUGvhaSR9TKL+m7RJsE+0zNreLBMoTjjedZEAgj9JKzs78wA7eXkh4qPuZ uB7r4kVOMhjNQfBESaGqI0C9GDJ+8FW0RhkQ7nrFEVsjf++12L+iBQHO4r8yujcJE5BpW +7ISTS58dF2DGwff6NgccpPpgQIKjZIBmBFvz+as0tY7Q8Ew/ef1xL+oJBzlzbfXKQL76 daV+qKmZyCWbp4Jf3Jt66Rnv47FbpcxjlEd+1Esvf41GFDftgyiHYvHT3yJaUSe99pI1s /BOsb65G0U9DdmjtG3AyPfK8wbUMwfIGBxhpgzxbjpAyy7cjpWpC/rseaapEhGcCWWg== 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=DqOMHF8v; 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 8343F606A31A; Wed, 28 Oct 2026 18:56:13 +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=DqOMHF8v Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9841F1F01825; Wed, 28 Oct 2026 18:56:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793213773; bh=51g+3I2HTKORk1mFF1gb75CkfimuaoL7jrcc4LBi0WM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=DqOMHF8v6ovKTPSw0XOaLq/2UKYKxNGYz1HxfC5QtrTViaOA7lYcKS7vqoSZRcX3O dlNly+nJV4WmcTKJCREfnvl4gejXLlcKw6cBL9tY46Be40m4k4Gn64JwlUAd1wm5O0 dGb2+KBwJzaOjU4RqZyHIxFrOp6MBYoB6s7sJRA4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yongqiang Sun , Anthony Koo , Rodrigo Siqueira , Aurabindo Pillai , Srinivasan Shanmugam , Alex Deucher , Sasha Levin Subject: [PATCH 6.1 0580/1887] drm/amd/display: Fix panel_cntl could be null in dcn21_set_backlight_level() Date: Wed, 28 Oct 2026 17:44:36 +0100 Message-ID: <20261028170512.616489617@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: Srinivasan Shanmugam [ Upstream commit e96fddb32931d007db12b1fce9b5e8e4c080401b ] 'panel_cntl' structure used to control the display panel could be null, dereferencing it could lead to a null pointer access. Fixes the below: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn21/dcn21_hwseq.c:269 dcn21_set_backlight_level() error: we previously assumed 'panel_cntl' could be null (see line 250) Fixes: 474ac4a875ca ("drm/amd/display: Implement some asic specific abm call backs.") Cc: Yongqiang Sun Cc: Anthony Koo Cc: Rodrigo Siqueira Cc: Aurabindo Pillai Signed-off-by: Srinivasan Shanmugam Reviewed-by: Anthony Koo Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hwseq.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hwseq.c index 13340ea84e7d0..5910cde0408d0 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hwseq.c @@ -207,16 +207,21 @@ bool dcn21_set_backlight_level(struct pipe_ctx *pipe_ctx, union dmub_rb_cmd cmd; struct dc_context *dc = pipe_ctx->stream->ctx; struct abm *abm = pipe_ctx->stream_res.abm; - uint32_t otg_inst = pipe_ctx->stream_res.tg->inst; + struct timing_generator *tg = pipe_ctx->stream_res.tg; struct panel_cntl *panel_cntl = pipe_ctx->stream->link->panel_cntl; + uint32_t otg_inst; + + if (!abm || !tg || !panel_cntl) + return false; + + otg_inst = tg->inst; if (dc->dc->res_pool->dmcu) { dce110_set_backlight_level(pipe_ctx, backlight_pwm_u16_16, frame_ramp); return true; } - if (abm && panel_cntl) - dmub_abm_set_pipe(abm, otg_inst, SET_ABM_PIPE_NORMAL, panel_cntl->inst); + dmub_abm_set_pipe(abm, otg_inst, SET_ABM_PIPE_NORMAL, panel_cntl->inst); memset(&cmd, 0, sizeof(cmd)); cmd.abm_set_backlight.header.type = DMUB_CMD__ABM; -- 2.53.0