From: Prarit Bhargava <prarit@redhat.com>
To: Bjorn Helgaas <helgaas@kernel.org>, Sasha Levin <sasha.levin@oracle.com>
Cc: bhelgaas@google.com, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] PCI: prevent out of bounds access in numa_node override
Date: Tue, 06 Oct 2015 16:02:22 -0400 [thread overview]
Message-ID: <561428CE.2040601@redhat.com> (raw)
In-Reply-To: <20151006193627.GE29420@localhost>
On 10/06/2015 03:36 PM, Bjorn Helgaas wrote:
> Hi Sasha,
>
> On Sun, Oct 04, 2015 at 05:49:29PM -0400, Sasha Levin wrote:
>> Commit 63692df1 ("PCI: Allow numa_node override via sysfs") didn't check that
>> the numa node provided by userspace is valid. Passing a node number too high
>> would attempt to access invalid memory and trigger a kernel panic.
>>
>> Fixes: 63692df1 ("PCI: Allow numa_node override via sysfs")
>> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
>> ---
>> drivers/pci/pci-sysfs.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
>> index 312f23a..e9abca8 100644
>> --- a/drivers/pci/pci-sysfs.c
>> +++ b/drivers/pci/pci-sysfs.c
>> @@ -216,7 +216,7 @@ static ssize_t numa_node_store(struct device *dev,
>> if (ret)
>> return ret;
>>
>> - if (!node_online(node))
>> + if (node > MAX_NUMNODES || !node_online(node))
>
> This needs to be "node >= MAX_NUMNODES", doesn't it? I'll fix it up if
> you agree.
Not a strenuous objection, but I don't see much bound checking using
MAX_NUMNODES in the kernel outside of the core numa area. Is fixing
node_online() with bounds checking a better option here so that other callers
get the fix? I would have thought that calling node_online() with node >
MAX_NUMNODES should be safe to call.
P.
>
> Looks like a candidate for stable.
>
>> return -EINVAL;
>>
>> add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
>> --
>> 1.7.10.4
>>
>> --
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> --
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>
next prev parent reply other threads:[~2015-10-06 20:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-04 21:49 [PATCH] PCI: prevent out of bounds access in numa_node override Sasha Levin
2015-10-06 19:36 ` Bjorn Helgaas
2015-10-06 20:02 ` Prarit Bhargava [this message]
2015-10-07 14:07 ` Sasha Levin
2015-10-07 16:04 ` Bjorn Helgaas
2015-10-07 16:09 ` Bjorn Helgaas
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