From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 3F4703EFFD2 for ; Fri, 9 Oct 2026 21:26:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791581221; cv=none; b=Xwsg0SMDo2QWKYORK9QG14X3jz4c/6WrIP9EDdxZvg3s3V+LNBOp+JuDEjisnUTpb9MiQFDikD7RD6f+tvPsaDkijrSy7Y8S7utzJTlwWVRXzGVoyPD0mDZCKiw4cwiw2OsnTec2hHyrnAiKv0eWNxFEkJJIfup7xcAt7acuiWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791581221; c=relaxed/simple; bh=TyxSOYU5PioABjr8EJeQo8NGMnez3v+D+t81pCkh7J4=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=KGyAXtfDlllR2394s2saY+Mx6BRSWcRjlLuLOfEJ+B2tJs/UmJv0d0Y139JZJtC/ovANRvnhTnR10ACP5LoD+669+FbNTg+JdP40EUqa9QM4aCvoGQFm9rpmMY2SSj9gpD2H7CqifPpxpGH76DqOVSIQQQJPCGsWrZCOJ8gFutg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=DHcvcGuz; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=B5+xXeBg; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DHcvcGuz"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="B5+xXeBg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1791581216; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZxvkTxUcJf7CaZriMxWB3wlk03saYsRAfT3CN9F3Ggk=; b=DHcvcGuzMAxIPT0KFFqHBTuQMEZZ3GOvfEn6TB4y8f0SCV7ev/QVdppzrDkFGWZW0wpueA 30jJYbc9PCSUfg0J5qke5GfLAqGJoezNNFHWQPHvvYt0Ca6c59W1BqgovMqdRylfHnhzth SWxmjaDhiXaY5mbFZh17Bm6BkgpYLFw= Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-584-geCr45PGPwqjpZDimZ7LZQ-1; Fri, 9 Oct 2026 21:26:55 +0000 X-MC-Unique: geCr45PGPwqjpZDimZ7LZQ-1 X-Mimecast-MFC-AGG-ID: geCr45PGPwqjpZDimZ7LZQ_1791581214 Received: by mail-qt1-f200.google.com with SMTP id d75a77b69052e-5345ded3f6dso3403991cf.3 for ; Fri, 09 Oct 2026 14:26:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1791581214; x=1792186014; darn=vger.kernel.org; h=mime-version:user-agent:content-transfer-encoding:content-type :references:in-reply-to:date:cc:to:from:subject:message-id:from:to :cc:subject:date:message-id:reply-to:content-type; bh=ZxvkTxUcJf7CaZriMxWB3wlk03saYsRAfT3CN9F3Ggk=; b=B5+xXeBgYtNcjTT1Nr7kDEV0T40IhHn7aXqUo2X4xNKJIkS81ESwog6Gt7BVokifZs sS765scpDTFvKaosT5z6cCjcte3HC2pMAr6eQ0IuYssYHBouJEaGkFDdkU96xDd3KlsJ 2kGgykZ+7/Yic9XZQYP61ByUZDla4mWjLOEjxfF/24/vDwegZ8E3A3IbASroJ7cEJQZq Kivg/bSe0mLWRtoIprZ5LaT40ZzuuPah1QtF2COCxhrHmCDfM/FlhAWCBJIRVqWphi2D +eE731iPELdRFw5PXN+9GCmoVLMspOaGIFvSpvjAQAfNsYg8mubGV17TA9IjIbzZKjAQ liCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791581214; x=1792186014; h=mime-version:user-agent:content-transfer-encoding:content-type :references:in-reply-to:date:cc:to:from:subject:message-id:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=ZxvkTxUcJf7CaZriMxWB3wlk03saYsRAfT3CN9F3Ggk=; b=vU8pdhOSWK080Qw49E9rbgRH1Yg2MSnw8Io6NLZPZJZZdKkuCr3uRKCV7Kx8/5LCyP zoTZwSFX3SuZshbOTxjbmFrpScgHM2amyhB/0WD9KGkNDpchDH2SZyHJRwb+O5OlZ0n1 Z1/2nIZMpbDKQFgZLOjaK1xjEs0VJ8S1OuNPLpmjExNN0lYs38Yuaa+917XjiM3kzbuF 4yNdKWEpgDBZpjwvC7uEzYjqQnutn+EhQmDIKUIRy4FzifrRtOy5LEvNfesN9WYeGzop wF/1sLFDmZGRxJ8iBz4GTtP3qSlSDcL/U/YVAYyXvauKNPqFZ0h0x+e4GtcmoQKYfciR s7Qg== X-Forwarded-Encrypted: i=1; AKwUvBz5JnH8+c+FZEyOYxwQ2P19ikCTBkaLhMZKz5IQnVuQXDsRayaspNLZgFsOssHMJIBqKYc5hPpIx1LCXYc=@vger.kernel.org X-Gm-Message-State: AFq9FYK+6nGS8YgVRsYruel7ODNFNpiv3S81QKuNT7tAVCjEr/w4ikqt Pb19Wj3d+USnkpTKxjU4NzveM+R604/PYHYUJarrKsw9wwPiPCvS6xiR5VkkyG1mUhLZB25ZvvI A2dDWpqO80wkGbKOLwvzoJvbmxDN2odSxCU7gKPbNVCwMu9tUZMtfVxbTlumUoOAWCg== X-Gm-Gg: AYBFou3FB2jwHkqd24FPtYTirRaj6kXRfma6JVkhamk93vrrSAITCim7KEm/hQ1BYn9 GA+Sc1p/CdO5t/M4sm588UUBzpA/3KhhtnyBmiGVoPty1Ggz3kO5V8HzcdVTY8heVlSyalrFvBA 61TcMuB7AgRp7ljCUaz5HcuuJ/QUXQns9WQ6R6fn6kH9FQ22kFuJWxamvJe5PiVoGSpunUCNREY 7b3BY8TXwXudcRVgIZ+c1+eddZfqXs3o/ZaZTsO13p9Y17t0U7UtexRy723IxFc2pTWQWc6ZgRZ OPquqo7+9JnJYn2wCu9qrV5DAVq+F6kli2etiI3LqSDxxYGggBlBR4g/sbIDWBbaXjkoGIM= X-Received: by 2002:a05:622a:343:b0:535:209a:2789 with SMTP id d75a77b69052e-5359fae42c4mr54673831cf.27.1791581214258; Fri, 09 Oct 2026 14:26:54 -0700 (PDT) X-Received: by 2002:a05:622a:343:b0:535:209a:2789 with SMTP id d75a77b69052e-5359fae42c4mr54673491cf.27.1791581213810; Fri, 09 Oct 2026 14:26:53 -0700 (PDT) Received: from [192.168.8.4] ([100.0.180.93]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5359b7c0214sm27166781cf.25.2026.10.09.14.26.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Oct 2026 14:26:53 -0700 (PDT) Message-ID: Subject: Re: [PATCH v2 3/3] nouveau: Fix NULL dereference in nvkm_gsp_gcx_ready() From: lyude@redhat.com To: jim.cromie@gmail.com, Danilo Krummrich , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Dave Airlie Cc: dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, Daniel Campos Ramos Date: Fri, 09 Oct 2026 17:26:52 -0400 In-Reply-To: <20261009-my-fixups-v2-3-839e2bbe514d@gmail.com> References: <20261009-my-fixups-v2-0-839e2bbe514d@gmail.com> <20261009-my-fixups-v2-3-839e2bbe514d@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.3 (3.58.3-2.fc43) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reviewed-by: Lyude Paul On Fri, 2026-10-09 at 11:44 -0600, Jim Cromie via B4 Relay wrote: > From: Jim Cromie >=20 > Commit cb4c7603678c ("drm/nouveau/gsp/r570: Add support for > INTERNAL_GCX_ENTRY_PREREQUISITE") hooked nvif_device_gcx_ready() into > nouveau_pmops_runtime_suspend() to consult GSP before runtime > suspend. >=20 > On GPUs running without GSP-RM (e.g. Volta GV100, NvGspRm=3D0, or > missing > GSP firmware blobs), device->gsp is instantiated but gsp->rm remains > NULL. nvkm_udevice_gcx_ready() checked "!gsp" instead of verifying > nvkm_gsp_rm(gsp), allowing non-RM instances to invoke > nvkm_gsp_gcx_ready(). nvkm_gsp_gcx_ready() then unconditionally > dereferenced gsp->rm->api, causing a kernel oops: >=20 > =C2=A0 RIP: 0010:nvkm_gsp_gcx_ready+0x10/0x30 [nouveau] > =C2=A0 Code: ... 48 8b 87 70 0e 00 00 <48> 8b 40 18 ... > =C2=A0 RAX: 0000000000000000 RDI: ffff8c9555fca000 > =C2=A0 Call Trace: > =C2=A0=C2=A0 nvkm_udevice_mthd+0xa5/0x150 [nouveau] > =C2=A0=C2=A0 nvkm_ioctl+0xcc/0x1d0 [nouveau] > =C2=A0=C2=A0 nvif_object_mthd+0x110/0x1e0 [nouveau] > =C2=A0=C2=A0 nvif_device_gcx_ready+0x36/0x60 [nouveau] > =C2=A0=C2=A0 nouveau_pmops_runtime_suspend+0x39/0x140 [nouveau] >=20 > Instruction decode shows `mov rax, [rdi+0xe70]` loads gsp->rm (0x0), > and `<48> 8b 40 18` (`mov rax, [rax+0x18]`) faults accessing rm->api. >=20 > Fix by: > 0. Checking !nvkm_gsp_rm(gsp) in nvkm_udevice_gcx_ready() so non-RM > =C2=A0=C2=A0 devices report GC6/GcOff ready and bypass the GSP call entir= ely. > 1. Guarding gsp and gsp->rm in nvkm_gsp_gcx_ready() before inspecting > =C2=A0=C2=A0 gsp->rm->api->gsp->gcx_ready. >=20 > Fixes: cb4c7603678c ("drm/nouveau/gsp/r570: Add support for > INTERNAL_GCX_ENTRY_PREREQUISITE") > Signed-off-by: Jim Cromie > --- > =C2=A0drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h | 2 +- > =C2=A0drivers/gpu/drm/nouveau/nvkm/engine/device/user.c | 2 +- > =C2=A0drivers/gpu/drm/nouveau/nvkm/subdev/gsp/base.c=C2=A0=C2=A0=C2=A0 | = 2 +- > =C2=A03 files changed, 3 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h > b/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h > index ed5c6e0e68d3..933f13ed2a50 100644 > --- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h > +++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h > @@ -274,7 +274,7 @@ struct nvkm_gsp { > =C2=A0static inline bool > =C2=A0nvkm_gsp_rm(struct nvkm_gsp *gsp) > =C2=A0{ > - return gsp && (gsp->fws.rm || gsp->fw.img); > + return gsp && gsp->rm && (gsp->fws.rm || gsp->fw.img); > =C2=A0} > =C2=A0 > =C2=A0#include > diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c > b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c > index f78e6b9b4292..d469437eb991 100644 > --- a/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c > +++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/user.c > @@ -201,7 +201,7 @@ nvkm_udevice_gcx_ready(struct nvkm_udevice *udev, > void *data, u32 size) > =C2=A0 } *args =3D data; > =C2=A0 int ret =3D -ENOSYS; > =C2=A0 > - if (!gsp) { > + if (!nvkm_gsp_rm(gsp)) { > =C2=A0 args->v0.ready =3D NV_DEVICE_GC6_READY | > NV_DEVICE_GCOFF_READY; > =C2=A0 return 0; > =C2=A0 } > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/base.c > b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/base.c > index e475d0e8fa7b..ea895f04293a 100644 > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/base.c > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/base.c > @@ -51,7 +51,7 @@ nvkm_gsp_intr_stall(struct nvkm_gsp *gsp, enum > nvkm_subdev_type type, int inst) > =C2=A0int > =C2=A0nvkm_gsp_gcx_ready(struct nvkm_gsp *gsp) > =C2=A0{ > - if (!gsp->rm->api->gsp->gcx_ready) > + if (!nvkm_gsp_rm(gsp) || !gsp->rm->api->gsp->gcx_ready) > =C2=A0 return NV_DEVICE_GC6_READY | NV_DEVICE_GCOFF_READY; > =C2=A0 > =C2=A0 return gsp->rm->api->gsp->gcx_ready(gsp);