Re: [Linux-kernel-mentees] [PATCH] PCI/IOV: Make SR-IOV attributes with mode 0664 use 0644

From: Bjorn Helgaas
Date: Thu Sep 05 2019 - 14:29:43 EST


[+cc Bodong, Eli: just FYI since this affects sriov_drivers_autoprobe,
which you added with 0e7df22401a3]

On Thu, Sep 05, 2019 at 12:32:26AM -0600, Kelsey Skunberg wrote:
> sriov_numvfs and sriov_drivers_autoprobe have "unusual" permissions (0664)
> with no reported or found reason for allowing group write permissions.
> libvirt runs as root when dealing with PCI, and chowns files for qemu
> needs. There is not a need for the "0664" permissions.
>
> sriov_numvfs was introduced in:
> commit 1789382a72a5 ("PCI: SRIOV control and status via sysfs")
>
> sriov_drivers_autoprobe was introduced in:
> commit 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to
> control VF driver binding")
>
> Change sriov_numvfs and sriov_drivers_autoprobe from "0664" permissions to
> "0644" permissions.
>
> Exchange DEVICE_ATTR() with DEVICE_ATTR_RW() which sets the mode to "0644".
> DEVICE_ATTR() should only be used for "unusual" permissions.
>
> Signed-off-by: Kelsey Skunberg <skunberg.kelsey@xxxxxxxxx>

Applied with Greg's Reviewed-by and Don's Acked-by to pci/misc for
v5.4, thanks!

> ---
> drivers/pci/iov.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index b335db21c85e..b3f972e8cfed 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -375,12 +375,11 @@ static ssize_t sriov_drivers_autoprobe_store(struct device *dev,
> }
>
> static DEVICE_ATTR_RO(sriov_totalvfs);
> -static DEVICE_ATTR(sriov_numvfs, 0664, sriov_numvfs_show, sriov_numvfs_store);
> +static DEVICE_ATTR_RW(sriov_numvfs);
> static DEVICE_ATTR_RO(sriov_offset);
> static DEVICE_ATTR_RO(sriov_stride);
> static DEVICE_ATTR_RO(sriov_vf_device);
> -static DEVICE_ATTR(sriov_drivers_autoprobe, 0664, sriov_drivers_autoprobe_show,
> - sriov_drivers_autoprobe_store);
> +static DEVICE_ATTR_RW(sriov_drivers_autoprobe);
>
> static struct attribute *sriov_dev_attrs[] = {
> &dev_attr_sriov_totalvfs.attr,
> --
> 2.20.1
>
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