From: Bjorn Helgaas <helgaas@kernel.org>
To: Ziming Du <duziming2@huawei.com>
Cc: bhelgaas@google.com, alex@shazbot.org, chrisw@redhat.com,
jbarnes@virtuousgeek.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, liuyongqiang13@huawei.com
Subject: Re: [PATCH v4 1/4] PCI/sysfs: Prohibit unaligned access to I/O port
Date: Thu, 26 Feb 2026 11:00:50 -0600 [thread overview]
Message-ID: <20260226170050.GA3812835@bhelgaas> (raw)
In-Reply-To: <20260116081723.1603603-2-duziming2@huawei.com>
On Fri, Jan 16, 2026 at 04:17:18PM +0800, Ziming Du wrote:
> Unaligned access is harmful for non-x86 archs such as arm64. When we
> use pwrite or pread to access the I/O port resources with unaligned
> offset, system will crash as follows:
> @@ -1166,12 +1167,16 @@ static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,
> *(u8 *)buf = inb(port);
> return 1;
> case 2:
> + if (!IS_ALIGNED(port, count))
> + return -EINVAL;
I assume "IS_ALIGNED(port, 1)" is *always* true, so can we just do
this once before the switch instead of adding it to the "case 2" and
"case 4"?
> if (write)
> outw(*(u16 *)buf, port);
> else
> *(u16 *)buf = inw(port);
> return 2;
> case 4:
> + if (!IS_ALIGNED(port, count))
> + return -EINVAL;
> if (write)
> outl(*(u32 *)buf, port);
> else
> --
> 2.43.0
>
next prev parent reply other threads:[~2026-02-26 17:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-16 8:17 [PATCH v4 0/4] Miscellaneous fixes for pci subsystem Ziming Du
2026-01-16 8:17 ` [PATCH v4 1/4] PCI/sysfs: Prohibit unaligned access to I/O port Ziming Du
2026-02-26 17:00 ` Bjorn Helgaas [this message]
2026-01-16 8:17 ` [PATCH v4 2/4] PCI/sysfs: Fix null pointer dereference during hotplug Ziming Du
2026-02-26 17:14 ` Bjorn Helgaas
2026-02-27 2:30 ` duziming
2026-04-02 7:23 ` duziming
2026-01-16 8:17 ` [PATCH v4 3/4] PCI: Prevent overflow in proc_bus_pci_write() Ziming Du
2026-03-03 19:32 ` Bjorn Helgaas
2026-01-16 8:17 ` [PATCH v4 4/4] PCI: Prevent overflow in proc_bus_pci_read() Ziming Du
2026-01-30 7:53 ` [PATCH v4 0/4] Miscellaneous fixes for pci subsystem duziming
2026-02-06 22:29 ` Bjorn Helgaas
2026-02-26 9:07 ` duziming
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