From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-103.mailbox.org (mout-p-103.mailbox.org [80.241.56.161]) (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 DEB2E1624F4; Wed, 5 Mar 2025 07:03:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.161 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741158229; cv=none; b=Ji2tEcAg0sQ8UFRUFzpev8Avv1+rWqmLEGob65yii6+KdCd5vHcLtpuUM3r3HKmzT3Kpo2X5tZUC1c7Ll0+fySiYzx1hj9o5Ul4fDOspYaHY/1exQYow7Yozh0leyx7KBvwFyl17L7+JNnpDX0kdeL6ncaqrAav8nS/3nzb166w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741158229; c=relaxed/simple; bh=q4xpQb+6+YSUnyImlArI6oWO4a/8VjfSPXyBOGk2qz8=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=QW+C5tOAGJLFRlqsYxz0et3B16pGEbqpKL3o9+lUg/s/r2M5qBnXWq6fUCALxRaMyV5fMzQSb+IWGpf/IO8x8WWoY3MhWWf6zFPd4rzTjJTEm8O7azUCX06W5lLaGrepBjLrDni5QGPQdgfxDL0/pCsrx++HSw2u30PLDGGYIQ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=aHc+QVBg; arc=none smtp.client-ip=80.241.56.161 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="aHc+QVBg" Received: from smtp102.mailbox.org (smtp102.mailbox.org [IPv6:2001:67c:2050:b231:465::102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-103.mailbox.org (Postfix) with ESMTPS id 4Z73Rt0TNyz9sSf; Wed, 5 Mar 2025 08:03:38 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1741158218; h=from:from:reply-to: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=DixBmUDBTMybbHMZPiht6bmfAxxM9bk/dkydsd/IiGA=; b=aHc+QVBgFG9RiL5iRcYoX7+bFjLQHHHrgiLW4uyiOsdjI8UDIEWgWOjAqHWDyJaU6EL+Bd 1qbBTecUktEzysYmuVpRiiekiIt4VQw+vIbzNXqt0oX4+IIuWi80T5DBMb2KKJgtfkSSD3 gXVGNEGc1SFGGwKxMT4L134idzhPBvx8Piq5Hm5eUhw0yelDnhGp2KrehwWjZojM+MbLqm Lu+0PieJ5zdm3LAYptcisTUbnGY7ToSYvm7qraw1+F4e4kYosEsapDgoswRwrJDQGC1i1L ONqyp8eQdMQURWDaWX2/UpPdvVdUOTfA109+KAfPUeaKqwwxQ46LcI44JtWuhg== Message-ID: Subject: Re: [PATCH] PCI: Check BAR index for validity From: Philipp Stanner Reply-To: phasta@kernel.org To: Philipp Stanner , Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Bingbu Cao Date: Wed, 05 Mar 2025 08:03:35 +0100 In-Reply-To: <20250304143112.104190-2-phasta@kernel.org> References: <20250304143112.104190-2-phasta@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MBO-RS-ID: e7f6647a2ca0481098c X-MBO-RS-META: scmt9z1poqkpkg19ieq8njqowunirj85 On Tue, 2025-03-04 at 15:31 +0100, Philipp Stanner wrote: > Many functions in PCI use accessor macros such as pci_resource_len(), > which take a BAR index. That index, however, is never checked for > validity, potentially resulting in undefined behavior by overflowing > the > array pci_dev.resource in the macro pci_resource_n(). >=20 > Since many users of those macros directly assign the accessed value > to > an unsigned integer, the macros cannot be changed easily anymore to > return -EINVAL for invalid indexes. Consequently, the problem has to > be > mitigated in higher layers. >=20 > Add pci_bar_index_valid(). Use it where appropriate. >=20 > Reported-by: Bingbu Cao > Closes: > https://lore.kernel.org/all/adb53b1f-29e1-3d14-0e61-351fd2d3ff0d@linux.in= tel.com/ > Signed-off-by: Philipp Stanner > --- > =C2=A0drivers/pci/devres.c | 16 ++++++++++++++-- > =C2=A0drivers/pci/iomap.c=C2=A0 | 30 +++++++++++++++++++++--------- > =C2=A0drivers/pci/pci.c=C2=A0=C2=A0=C2=A0 |=C2=A0 6 ++++++ > =C2=A0drivers/pci/pci.h=C2=A0=C2=A0=C2=A0 |=C2=A0 8 ++++++++ > =C2=A04 files changed, 49 insertions(+), 11 deletions(-) >=20 > diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c > index 3431a7df3e0d..d2c09589c537 100644 > --- a/drivers/pci/devres.c > +++ b/drivers/pci/devres.c > @@ -577,7 +577,7 @@ static int > pcim_add_mapping_to_legacy_table(struct pci_dev *pdev, > =C2=A0{ > =C2=A0 void __iomem **legacy_iomap_table; > =C2=A0 > - if (bar >=3D PCI_STD_NUM_BARS) > + if (!pci_bar_index_is_valid(bar)) > =C2=A0 return -EINVAL; > =C2=A0 > =C2=A0 legacy_iomap_table =3D (void __iomem > **)pcim_iomap_table(pdev); > @@ -622,7 +622,7 @@ static void > pcim_remove_bar_from_legacy_table(struct pci_dev *pdev, int bar) > =C2=A0{ > =C2=A0 void __iomem **legacy_iomap_table; > =C2=A0 > - if (bar >=3D PCI_STD_NUM_BARS) > + if (!pci_bar_index_is_valid(bar)) > =C2=A0 return; > =C2=A0 > =C2=A0 legacy_iomap_table =3D (void __iomem > **)pcim_iomap_table(pdev); > @@ -655,6 +655,9 @@ void __iomem *pcim_iomap(struct pci_dev *pdev, > int bar, unsigned long maxlen) > =C2=A0 void __iomem *mapping; > =C2=A0 struct pcim_addr_devres *res; > =C2=A0 > + if (!pci_bar_index_is_valid(bar)) > + return NULL; > + > =C2=A0 res =3D pcim_addr_devres_alloc(pdev); > =C2=A0 if (!res) > =C2=A0 return NULL; > @@ -722,6 +725,9 @@ void __iomem *pcim_iomap_region(struct pci_dev > *pdev, int bar, > =C2=A0 int ret; > =C2=A0 struct pcim_addr_devres *res; > =C2=A0 > + if (!pci_bar_index_is_valid(bar)) > + return IOMEM_ERR_PTR(-EINVAL); > + > =C2=A0 res =3D pcim_addr_devres_alloc(pdev); > =C2=A0 if (!res) > =C2=A0 return IOMEM_ERR_PTR(-ENOMEM); > @@ -823,6 +829,9 @@ static int _pcim_request_region(struct pci_dev > *pdev, int bar, const char *name, > =C2=A0 int ret; > =C2=A0 struct pcim_addr_devres *res; > =C2=A0 > + if (!pci_bar_index_is_valid(bar)) > + return -EINVAL; > + > =C2=A0 res =3D pcim_addr_devres_alloc(pdev); > =C2=A0 if (!res) > =C2=A0 return -ENOMEM; > @@ -991,6 +1000,9 @@ void __iomem *pcim_iomap_range(struct pci_dev > *pdev, int bar, > =C2=A0 void __iomem *mapping; > =C2=A0 struct pcim_addr_devres *res; > =C2=A0 > + if (!pci_bar_index_is_valid(bar)) > + return IOMEM_ERR_PTR(-EINVAL); > + > =C2=A0 res =3D pcim_addr_devres_alloc(pdev); > =C2=A0 if (!res) > =C2=A0 return IOMEM_ERR_PTR(-ENOMEM); > diff --git a/drivers/pci/iomap.c b/drivers/pci/iomap.c > index 9fb7cacc15cd..0cab82cbcc99 100644 > --- a/drivers/pci/iomap.c > +++ b/drivers/pci/iomap.c > @@ -9,6 +9,8 @@ > =C2=A0 > =C2=A0#include > =C2=A0 > +#include "pci.h" /* for pci_bar_index_is_valid() */ > + > =C2=A0/** > =C2=A0 * pci_iomap_range - create a virtual mapping cookie for a PCI BAR > =C2=A0 * @dev: PCI device that owns the BAR > @@ -33,12 +35,18 @@ void __iomem *pci_iomap_range(struct pci_dev > *dev, > =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 unsigned long offset, > =C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 unsigned long maxlen) > =C2=A0{ > - resource_size_t start =3D pci_resource_start(dev, bar); > - resource_size_t len =3D pci_resource_len(dev, bar); > - unsigned long flags =3D pci_resource_flags(dev, bar); > + resource_size_t start, len; > + unsigned long flags; > =C2=A0 > + if (!pci_bar_index_is_valid(bar)) > + return NULL; > =C2=A0 if (len <=3D offset || !start) > =C2=A0 return NULL; Argh, damn, this is a bug of course. 'start' is undefined at this point, as is 'len'. > + > + start =3D pci_resource_start(dev, bar); > + len =3D pci_resource_len(dev, bar); > + flags =3D pci_resource_flags(dev, bar); > + > =C2=A0 len -=3D offset; > =C2=A0 start +=3D offset; > =C2=A0 if (maxlen && len > maxlen) > @@ -77,17 +85,21 @@ void __iomem *pci_iomap_wc_range(struct pci_dev > *dev, > =C2=A0 unsigned long offset, > =C2=A0 unsigned long maxlen) > =C2=A0{ > - resource_size_t start =3D pci_resource_start(dev, bar); > - resource_size_t len =3D pci_resource_len(dev, bar); > - unsigned long flags =3D pci_resource_flags(dev, bar); > - > + resource_size_t start, len; > + unsigned long flags; > =C2=A0 > - if (flags & IORESOURCE_IO) > + if (!pci_bar_index_is_valid(bar)) > =C2=A0 return NULL; > - > =C2=A0 if (len <=3D offset || !start) > =C2=A0 return NULL; Same here. Shall I send a v2 or do you want to rebase, Bjorn? sry bout that. P. > =C2=A0 > + start =3D pci_resource_start(dev, bar); > + len =3D pci_resource_len(dev, bar); > + flags =3D pci_resource_flags(dev, bar); > + > + if (flags & IORESOURCE_IO) > + return NULL; > + > =C2=A0 len -=3D offset; > =C2=A0 start +=3D offset; > =C2=A0 if (maxlen && len > maxlen) > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 869d204a70a3..da82d734d09c 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -3921,6 +3921,9 @@ EXPORT_SYMBOL(pci_enable_atomic_ops_to_root); > =C2=A0 */ > =C2=A0void pci_release_region(struct pci_dev *pdev, int bar) > =C2=A0{ > + if (!pci_bar_index_is_valid(bar)) > + return; > + > =C2=A0 /* > =C2=A0 * This is done for backwards compatibility, because the old > PCI devres > =C2=A0 * API had a mode in which the function became managed if it > had been > @@ -3965,6 +3968,9 @@ EXPORT_SYMBOL(pci_release_region); > =C2=A0static int __pci_request_region(struct pci_dev *pdev, int bar, > =C2=A0 const char *name, int exclusive) > =C2=A0{ > + if (!pci_bar_index_is_valid(bar)) > + return -EINVAL; > + > =C2=A0 if (pci_is_managed(pdev)) { > =C2=A0 if (exclusive =3D=3D IORESOURCE_EXCLUSIVE) > =C2=A0 return pcim_request_region_exclusive(pdev, > bar, name); > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 01e51db8d285..ae8b2f5c118b 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -167,6 +167,14 @@ static inline void pci_wakeup_event(struct > pci_dev *dev) > =C2=A0 pm_wakeup_event(&dev->dev, 100); > =C2=A0} > =C2=A0 > +static inline bool pci_bar_index_is_valid(int bar) > +{ > + if (bar < 0 || bar >=3D PCI_NUM_RESOURCES) > + return false; > + > + return true; > +} > + > =C2=A0static inline bool pci_has_subordinate(struct pci_dev *pci_dev) > =C2=A0{ > =C2=A0 return !!(pci_dev->subordinate);