Revert "nbd: fix possible overflow on 'first_minor' in nbd_dev_add()"
This reverts commit 6d35d04a9e18990040e87d2bbf72689252669d54.
Both Gabriel and Borislav report that this commit casues a regression
with nbd:
sysfs: cannot create duplicate filename '/dev/block/43:0'
Revert it before 5.18-rc1 and we'll investigage this separately in
due time.
Link: https://lore.kernel.org/all/YkiJTnFOt9bTv6A2@zn.tnic/
Reported-by: Gabriel L. Somlo <somlo@cmu.edu>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index b3cdfc0..5a1f984 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1800,6 +1800,17 @@
refcount_set(&nbd->refs, 0);
INIT_LIST_HEAD(&nbd->list);
disk->major = NBD_MAJOR;
+
+ /* Too big first_minor can cause duplicate creation of
+ * sysfs files/links, since index << part_shift might overflow, or
+ * MKDEV() expect that the max bits of first_minor is 20.
+ */
+ disk->first_minor = index << part_shift;
+ if (disk->first_minor < index || disk->first_minor > MINORMASK) {
+ err = -EINVAL;
+ goto out_free_work;
+ }
+
disk->minors = 1 << part_shift;
disk->fops = &nbd_fops;
disk->private_data = nbd;
@@ -1904,19 +1915,8 @@
if (!netlink_capable(skb, CAP_SYS_ADMIN))
return -EPERM;
- if (info->attrs[NBD_ATTR_INDEX]) {
+ if (info->attrs[NBD_ATTR_INDEX])
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
-
- /*
- * Too big first_minor can cause duplicate creation of
- * sysfs files/links, since index << part_shift might overflow, or
- * MKDEV() expect that the max bits of first_minor is 20.
- */
- if (index < 0 || index > MINORMASK >> part_shift) {
- printk(KERN_ERR "nbd: illegal input index %d\n", index);
- return -EINVAL;
- }
- }
if (!info->attrs[NBD_ATTR_SOCKETS]) {
printk(KERN_ERR "nbd: must specify at least one socket\n");
return -EINVAL;
