| Message ID | 20200617103412.GA2027053@kroah.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Revert "zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()" | expand |
On 6/17/20 12:34 PM, Greg Kroah-Hartman wrote: > From: Wade Mealing <wmealing@redhat.com> > > Turns out that the permissions for 0400 really are what we want here, > otherwise any user can write to this file. Minor confusion on my side: Did you mean "read from" instead of "write to"? I.e. only owner may read but not group nor others. Whereas using CLASS_ATTR_RO would resolve into 0444. > > [fixed formatting and made static - gregkh] > > Reported-by: Wade Mealing <wmealing@redhat.com> > Cc: stable <stable@vger.kernel.org> > Fixes: f40609d1591f ("zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()") > Link: https://bugzilla.redhat.com/show_bug.cgi?id=1847832 > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > drivers/block/zram/zram_drv.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index 6e2ad90b17a3..270dd810be54 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -2021,7 +2021,8 @@ static ssize_t hot_add_show(struct class *class, > return ret; > return scnprintf(buf, PAGE_SIZE, "%d\n", ret); > } > -static CLASS_ATTR_RO(hot_add); > +static struct class_attribute class_attr_hot_add = > + __ATTR(hot_add, 0400, hot_add_show, NULL); > > static ssize_t hot_remove_store(struct class *class, > struct class_attribute *attr, >
On Wed, Jun 17, 2020 at 01:05:54PM +0200, Steffen Maier wrote: > On 6/17/20 12:34 PM, Greg Kroah-Hartman wrote: > > From: Wade Mealing <wmealing@redhat.com> > > > > Turns out that the permissions for 0400 really are what we want here, > > otherwise any user can write to this file. > > Minor confusion on my side: > Did you mean "read from" instead of "write to"? > I.e. only owner may read but not group nor others. > Whereas using CLASS_ATTR_RO would resolve into 0444. Sorry, you are correct, I'll fix the changelog text and send this out again. It's a "fun" file, reading from it causes something to happen, not the normal way things work :( greg k-h
Hi Greg, On Wed, Jun 17, 2020 at 12:34:12PM +0200, Greg Kroah-Hartman wrote: > From: Wade Mealing <wmealing@redhat.com> > > Turns out that the permissions for 0400 really are what we want here, > otherwise any user can write to this file. ^^^^^^^^ s/write to/read from/ As Wade reported, it's sufficient to read from it to create a zram entry. Regards, Willy
On Wed, Jun 17, 2020 at 02:31:00PM +0200, Willy Tarreau wrote: > Hi Greg, > > On Wed, Jun 17, 2020 at 12:34:12PM +0200, Greg Kroah-Hartman wrote: > > From: Wade Mealing <wmealing@redhat.com> > > > > Turns out that the permissions for 0400 really are what we want here, > > otherwise any user can write to this file. > ^^^^^^^^ > s/write to/read from/ > > As Wade reported, it's sufficient to read from it to create a zram entry. Bah I just saw your v2 now, sorry for the noise. Willy
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 6e2ad90b17a3..270dd810be54 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2021,7 +2021,8 @@ static ssize_t hot_add_show(struct class *class, return ret; return scnprintf(buf, PAGE_SIZE, "%d\n", ret); } -static CLASS_ATTR_RO(hot_add); +static struct class_attribute class_attr_hot_add = + __ATTR(hot_add, 0400, hot_add_show, NULL); static ssize_t hot_remove_store(struct class *class, struct class_attribute *attr,