On Fri, 10 Apr 2026, Krzysztof Wilczyński wrote: > Currently, the __resource_resize_store() allows writing to the > resourceN_resize sysfs attribute to change a BAR's size without > checking for capabilities, currently relying only on the file > access check. > > Resizing a BAR modifies PCI device configuration and can disrupt > active drivers. After the upcoming conversion to static attributes, > it will also trigger resource file updates via sysfs_update_groups(). > > Thus, add a CAP_SYS_ADMIN check to prevent unprivileged users from > performing BAR resize operations. > > Signed-off-by: Krzysztof Wilczyński <[email protected]> > --- > drivers/pci/pci-sysfs.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index ac4e7c516e78..6b8c8e62f68a 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -1619,6 +1619,9 @@ static ssize_t __resource_resize_store(struct device > *dev, int n, > int ret; > u16 cmd; > > + if (!capable(CAP_SYS_ADMIN)) > + return -EPERM; > + > if (kstrtoul(buf, 0, &size) < 0) > return -EINVAL; > >
Reviewed-by: Ilpo Järvinen <[email protected]> -- i.
