[PATCH] Revert "zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()"

[Tim Gardner]

From: Wade Mealing <wmealing at redhat.com>

CVE-020-10781

Turns out that the permissions for 0400 really are what we want here,
otherwise any user can read from this file.

[fixed formatting, added changelog, and made attribute static - gregkh]

Reported-by: Wade Mealing <wmealing at redhat.com>
Cc: stable <stable at vger.kernel.org>
Fixes: f40609d1591f ("zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1847832
Reviewed-by: Steffen Maier <maier at linux.ibm.com>
Acked-by: Minchan Kim <minchan at kernel.org>
Link: https://lore.kernel.org/r/20200617114946.GA2131650@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit 853eab68afc80f59f36bbdeb715e5c88c501e680)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 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 1bdb5793842b..a928c97b0467 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2026,7 +2026,8 @@ 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,
-- 
2.17.1