All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: linux-block <linux-block@vger.kernel.org>
Subject: [PATCH] block: check minor range in device_add_disk()
Date: Fri, 17 Dec 2021 23:51:25 +0900	[thread overview]
Message-ID: <b1b19379-23ee-5379-0eb5-94bf5f79f1b4@i-love.sakura.ne.jp> (raw)

ioctl(fd, LOOP_CTL_ADD, 1048576) causes

  sysfs: cannot create duplicate filename '/dev/block/7:0'

message because such request is treated as if ioctl(fd, LOOP_CTL_ADD, 0)
due to MINORMASK == 1048575. Verify that all minor numbers for that device
fit in the minor range.

Reported-by: wangyangbo <wangyangbo@uniontech.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
 block/genhd.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index 30362aeacac4..b6a278f54f34 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -425,6 +425,8 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
 				DISK_MAX_PARTS);
 			disk->minors = DISK_MAX_PARTS;
 		}
+		if (disk->first_minor + disk->minors > MINORMASK + 1)
+			return -EINVAL;
 	} else {
 		if (WARN_ON(disk->minors))
 			return -EINVAL;
-- 
2.32.0


             reply	other threads:[~2021-12-17 14:51 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-17 14:51 Tetsuo Handa [this message]
2021-12-21 16:19 ` [PATCH] block: check minor range in device_add_disk() Christoph Hellwig
2021-12-21 16:34 ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=b1b19379-23ee-5379-0eb5-94bf5f79f1b4@i-love.sakura.ne.jp \
    --to=penguin-kernel@i-love.sakura.ne.jp \
    --cc=linux-block@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.