From nobody Mon Feb 9 06:02:30 2026 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2339A79CF for ; Sun, 31 Mar 2024 06:46:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.149.199.84 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711867577; cv=none; b=botBRkid5ZZ+Cvn/ZfdR283S+2FFpqCE6OEKksJe7L7DYXJeB2coZSZ7EuGUEd1y5v7UEc6yjgmVKUDFXuhdKWfdPyJ/biZLMcnPsGi16GnjdNQXiwCmELb1OK22m11+Cgj/QhIy0048YfZYNt/LQT1m9xBLnJm24Kcyzxow2Nw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711867577; c=relaxed/simple; bh=YBKGUG6xwLwd/efnk+1ZzvtR165fqMeCotqx2Uv9AM0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=J5I2lJ8Kf07q+6+oj3uBtPtf5b0Thjls8tBg176d/alSNV3hmmrjr9pKZJyAFz7fK3DxzxN9jLR0Ur+nNOGfBLK8SSAFJqK4YQoEsKoC+1dC5+f2p9DKKwwP2VuL0QMGAkHENn8mQsIVWPdiuA82zycnVeMenaXXncud6VK4wjM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ispras.ru; spf=pass smtp.mailfrom=ispras.ru; dkim=pass (1024-bit key) header.d=ispras.ru header.i=@ispras.ru header.b=k0FTnHnY; arc=none smtp.client-ip=83.149.199.84 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ispras.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ispras.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ispras.ru header.i=@ispras.ru header.b="k0FTnHnY" Received: from tundra.lovozera (unknown [46.138.86.221]) by mail.ispras.ru (Postfix) with ESMTPSA id 5F9F140755D8; Sun, 31 Mar 2024 06:46:03 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.ispras.ru 5F9F140755D8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ispras.ru; s=default; t=1711867563; bh=Um1OeF+YjMXHeUez/kZLspj1wOkVZEI9a9MFeGLZNZo=; h=From:To:Cc:Subject:Date:From; b=k0FTnHnYTdvZURFzBOOYPMVCPYR5A2omqFTQlaRaFzwnHARsJT5Fj5QwrdRktR9J4 jfced4TYeae7QRKyV7KkJAxZ6BKdeu6N9q/CkaJifFd002w0QdMN212n6YwWnY9sMl MUPYvIcBMG5fcxw/67QvuSkNbhV2WhInMT96d9dI= From: Mikhail Kobuk To: Karol Herbst Cc: Mikhail Kobuk , Lyude Paul , Danilo Krummrich , David Airlie , Daniel Vetter , Ben Skeggs , Francisco Jerez , dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org, Fedor Pchelkin , Alexey Khoroshilov Subject: [PATCH] drm: nv04: Add check to avoid out of bounds access Date: Sun, 31 Mar 2024 09:45:51 +0300 Message-ID: <20240331064552.6112-1-m.kobuk@ispras.ru> X-Mailer: git-send-email 2.44.0 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 Content-Type: text/plain; charset="utf-8" Output Resource (dcb->or) value is not guaranteed to be non-zero (i.e. in drivers/gpu/drm/nouveau/nouveau_bios.c, in 'fabricate_dcb_encoder_table(= )' 'dcb->or' is assigned value '0' in call to 'fabricate_dcb_output()'). Add check to validate 'dcb->or' before it's used. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 2e5702aff395 ("drm/nouveau: fabricate DCB encoder table for iMac G4") Signed-off-by: Mikhail Kobuk --- drivers/gpu/drm/nouveau/dispnv04/dac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/dispnv04/dac.c b/drivers/gpu/drm/nouve= au/dispnv04/dac.c index d6b8e0cce2ac..0c8d4fc95ff3 100644 --- a/drivers/gpu/drm/nouveau/dispnv04/dac.c +++ b/drivers/gpu/drm/nouveau/dispnv04/dac.c @@ -428,7 +428,7 @@ void nv04_dac_update_dacclk(struct drm_encoder *encoder= , bool enable) struct drm_device *dev =3D encoder->dev; struct dcb_output *dcb =3D nouveau_encoder(encoder)->dcb; =20 - if (nv_gf4_disp_arch(dev)) { + if (nv_gf4_disp_arch(dev) && ffs(dcb->or)) { uint32_t *dac_users =3D &nv04_display(dev)->dac_users[ffs(dcb->or) - 1]; int dacclk_off =3D NV_PRAMDAC_DACCLK + nv04_dac_output_offset(encoder); uint32_t dacclk =3D NVReadRAMDAC(dev, 0, dacclk_off); @@ -453,7 +453,7 @@ bool nv04_dac_in_use(struct drm_encoder *encoder) struct drm_device *dev =3D encoder->dev; struct dcb_output *dcb =3D nouveau_encoder(encoder)->dcb; =20 - return nv_gf4_disp_arch(encoder->dev) && + return nv_gf4_disp_arch(encoder->dev) && ffs(dcb->or) && (nv04_display(dev)->dac_users[ffs(dcb->or) - 1] & ~(1 << dcb->index)); } =20 --=20 2.44.0