From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Niklas Cassel <niklas.cassel@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>,
Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
Bjorn Helgaas <bhelgaas@google.com>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI: dwc: fix find_next_bit() usage
Date: Tue, 15 Oct 2019 16:34:19 +0100 [thread overview]
Message-ID: <20191015153418.GB25674@e121166-lin.cambridge.arm.com> (raw)
In-Reply-To: <20190904160339.2800-1-niklas.cassel@linaro.org>
On Wed, Sep 04, 2019 at 06:03:38PM +0200, Niklas Cassel wrote:
> find_next_bit() takes a parameter of size long, and performs arithmetic
> that assumes that the argument is of size long.
>
> Therefore we cannot pass a u32, since this will cause find_next_bit()
> to read outside the stack buffer and will produce the following print:
> BUG: KASAN: stack-out-of-bounds in find_next_bit+0x38/0xb0
>
> Fixes: 1b497e6493c4 ("PCI: dwc: Fix uninitialized variable in dw_handle_msi_irq()")
> Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
> ---
> drivers/pci/controller/dwc/pcie-designware-host.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
Applied to pci/dwc, thanks.
Lorenzo
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index d3156446ff27..45f21640c977 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -78,7 +78,8 @@ static struct msi_domain_info dw_pcie_msi_domain_info = {
> irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
> {
> int i, pos, irq;
> - u32 val, num_ctrls;
> + unsigned long val;
> + u32 status, num_ctrls;
> irqreturn_t ret = IRQ_NONE;
>
> num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
> @@ -86,14 +87,14 @@ irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
> for (i = 0; i < num_ctrls; i++) {
> dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS +
> (i * MSI_REG_CTRL_BLOCK_SIZE),
> - 4, &val);
> - if (!val)
> + 4, &status);
> + if (!status)
> continue;
>
> ret = IRQ_HANDLED;
> + val = status;
> pos = 0;
> - while ((pos = find_next_bit((unsigned long *) &val,
> - MAX_MSI_IRQS_PER_CTRL,
> + while ((pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL,
> pos)) != MAX_MSI_IRQS_PER_CTRL) {
> irq = irq_find_mapping(pp->irq_domain,
> (i * MAX_MSI_IRQS_PER_CTRL) +
> --
> 2.21.0
>
prev parent reply other threads:[~2019-10-15 15:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 16:03 [PATCH] PCI: dwc: fix find_next_bit() usage Niklas Cassel
2019-09-12 11:31 ` Gustavo Pimentel
2019-09-12 13:04 ` Andrew Murray
2019-09-13 21:57 ` Bjorn Andersson
2019-10-15 15:34 ` Lorenzo Pieralisi [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191015153418.GB25674@e121166-lin.cambridge.arm.com \
--to=lorenzo.pieralisi@arm.com \
--cc=bhelgaas@google.com \
--cc=gustavo.pimentel@synopsys.com \
--cc=jingoohan1@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=niklas.cassel@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).