From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Skripkin Subject: [PATCH] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group Date: Sat, 12 Jun 2021 17:05:59 +0300 Message-ID: <20210612140559.20022-1-paskripkin@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=5JZMHW5UG5CyvDN0SOE2Y9hqb0tFNng+vhQJCVqivJ8=; b=D6A/v3863n804431JpJ/EPCUtfVYDzi5Uhzhb4quMvA3+UiYYEvk1ssSEFIblDNXjC fduAtA1lKSPuxgPLQ1aIklkw8rwfDwxNlOJgWtwURLw/DCPAXr4mHVcxF4wD1R/bgMx/ OJ3EKf41fIzJJkYiWoQu8gZ1qgV6zWqngjpvUZmSLJC2zIUaKz6JsnM+uTv42IY3f7O4 APCOatnS29cF08zfcyOzV0CGUbWgukwmnxsc6/GlA8V0Jkehu7zGnpF5Heg09wES22i0 37haeWAjqYEcrjqK6G3pI5MrbZrP+cr8TwuA3A7ubAFNxsTSlkEhYVnKnx36yKOsgSlk KeRw== List-ID: Content-Type: text/plain; charset="us-ascii" To: konishi.ryusuke-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Vyacheslav.Dubeyko-XckBA8eALwE@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org Cc: linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Pavel Skripkin My local syzbot instance hit memory leak in nilfs2. The problem was in missing kobject_put() in nilfs_sysfs_delete_device_group(). kobject_del() does not call kobject_cleanup() for passed kobject and it leads to leaking duped kobject name if kobject_put() was not called. Fail log: BUG: memory leak unreferenced object 0xffff8880596171e0 (size 8): comm "syz-executor379", pid 8381, jiffies 4294980258 (age 21.100s) hex dump (first 8 bytes): 6c 6f 6f 70 30 00 00 00 loop0... backtrace: [] kstrdup+0x36/0x70 mm/util.c:60 [] kstrdup_const+0x53/0x80 mm/util.c:83 [] kvasprintf_const+0x108/0x190 lib/kasprintf.c:48 [] kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 [] kobject_add_varg lib/kobject.c:384 [inline] [] kobject_init_and_add+0xc9/0x160 lib/kobject.c:473 [] nilfs_sysfs_create_device_group+0x150/0x800 fs/nilfs2/sysfs.c:999 [] init_nilfs+0xe26/0x12b0 fs/nilfs2/the_nilfs.c:637 Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/ group") Signed-off-by: Pavel Skripkin --- fs/nilfs2/sysfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c index 303d71430bdd..9c6c0e2e5880 100644 --- a/fs/nilfs2/sysfs.c +++ b/fs/nilfs2/sysfs.c @@ -1053,6 +1053,7 @@ void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs) nilfs_sysfs_delete_superblock_group(nilfs); nilfs_sysfs_delete_segctor_group(nilfs); kobject_del(&nilfs->ns_dev_kobj); + kobject_put(&nilfs->ns_dev_kobj); kfree(nilfs->ns_dev_subgroups); } -- 2.32.0