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authorJens Axboe <axboe@kernel.dk>2022-04-02 11:40:23 -0600
committerJens Axboe <axboe@kernel.dk>2022-04-02 11:40:23 -0600
commit7198bfc2017644c6b92d2ecef9b8b8e0363bb5fd (patch)
treec1ff0a42197d43390cffb77c50018954ff9135e9 /drivers
parent2651ee5ae43241831ca63d7158bb2b151a6a0e1f (diff)
downloadlinux-7198bfc2017644c6b92d2ecef9b8b8e0363bb5fd.tar.bz2
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/nbd.c24
1 files changed, 12 insertions, 12 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index b3cdfc0ffb98..5a1f98494ddd 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1800,6 +1800,17 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
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 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
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;