From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta0.migadu.com (out-173.mta0.migadu.com [91.218.175.173]) (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 D6AF81ACEDE for ; Sat, 2 May 2026 12:13:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777724029; cv=none; b=lzeWK2wc2TUdBdRCk3Djvy/kNI29XrGf6+2Ha6h1WNwOkmDyPgbfs1qSmev4QJ9fRApYjDILkKwx0Qb4Ma1mTANoN0rJKhdot7QRsD0t2J2yufNiNFwBqjNTbwqe1aBlzGkjzjAi/Ne+IVVUmQYymmbjlqwoZTDRRVSG4SQvZv0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777724029; c=relaxed/simple; bh=XGytLSpCy9xgPusgWlXyFNDJcqnNgBnFVfmi4WwGiUQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=iK26TUYHwAgGCYaSGO2AeDT9iPWmBcjKH2Eh/jtm778oxZLgiZpYpknMIdY4nmk42hevZsO+57nhrtaDZbPIbpePnFsmEasYEC+GqfKZTNQgVDkjG4sUOOmUpM6FFrk3Xld0mkCGAdKzI1ef0ds6ZGGCpjYmFiHELAhfeghmHdo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=KH3+Iwab; arc=none smtp.client-ip=91.218.175.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="KH3+Iwab" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1777724024; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=7Fv9ANxoEXrJtQ42FBdd7xju+ouJmyQSyIcqfR7al/c=; b=KH3+IwabzQKYT0Bo9H+H3OSvvlqon/GATLmavjjC1jtoD69F+b11yP7Y0V7kYt8/aPvhGJ J42OKHRhEOQDrziuEcc8t1L7yDbcrodfjIHV3CAE3otKQvtpmm+85dUxpZGdLX17LvsElj FnBS+HcwxOp7UU7sccDL6lFz/6ve7o4= From: Thorsten Blum To: Maxime Ripard , Dave Stevenson , =?UTF-8?q?Ma=C3=ADra=20Canal?= , Raspberry Pi Kernel Maintenance , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Eric Anholt Cc: Thorsten Blum , stable@vger.kernel.org, Simona Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/vc4: fix NULL dereference in vc4_hvs_unbind Date: Sat, 2 May 2026 14:12:53 +0200 Message-ID: <20260502121251.39206-3-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1289; i=thorsten.blum@linux.dev; h=from:subject; bh=XGytLSpCy9xgPusgWlXyFNDJcqnNgBnFVfmi4WwGiUQ=; b=owGbwMvMwCUWt7pQ4caZUj3G02pJDJlfXzlH2FxsyOraNNE86c+LeJdUwfPfqwr4VKayegXul X6/yIKjo5SFQYyLQVZMkeXBrB8zfEtrKjeZROyEmcPKBDKEgYtTACYy5wYjQ9+Tjq2bGKvErzEU BDg//Jdz4OyKxA+L/17h5/D5XrhLoYbhf0CF8Frm1Xd4/MUenb+3Z53CqlfbHp5vmFmhGqO9Npu fhQMA X-Developer-Key: i=thorsten.blum@linux.dev; a=openpgp; fpr=1D60735E8AEF3BE473B69D84733678FD8DFEEAD4 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT With 'dtoverlay=vc4-kms-v3d,noaudio' and 'hdmi=off' on Raspberry Pi, unloading the vc4 module calls vc4_hvs_unbind() with dev_get_drvdata(master) returning NULL. Return early when 'drm' is NULL before converting it to 'vc4' and before dereferencing 'vc4->hvs', preventing a kernel oops. Fixes: c8b75bca92cb ("drm/vc4: Add KMS support for Raspberry Pi.") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum --- drivers/gpu/drm/vc4/vc4_hvs.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c index ee8d0738501b..9cb66f696fc7 100644 --- a/drivers/gpu/drm/vc4/vc4_hvs.c +++ b/drivers/gpu/drm/vc4/vc4_hvs.c @@ -1753,10 +1753,16 @@ static void vc4_hvs_unbind(struct device *dev, struct device *master, void *data) { struct drm_device *drm = dev_get_drvdata(master); - struct vc4_dev *vc4 = to_vc4_dev(drm); - struct vc4_hvs *hvs = vc4->hvs; + struct vc4_dev *vc4; + struct vc4_hvs *hvs; struct drm_mm_node *node, *next; + if (!drm) + return; + + vc4 = to_vc4_dev(drm); + hvs = vc4->hvs; + if (drm_mm_node_allocated(&vc4->hvs->mitchell_netravali_filter)) drm_mm_remove_node(&vc4->hvs->mitchell_netravali_filter);