From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.19 06/10] nilfs2: fix NULL pointer in nilfs_##name##_attr_release Date: Mon, 13 Sep 2021 18:35:17 -0400 Message-ID: <20210913223521.436250-6-sashal@kernel.org> References: <20210913223521.436250-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631572529; bh=cTg0XQYisPWumgunZBEDqjWz7SV7k3sH8/WB6KzyuQU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gfbWPKbjKc6VQrUpDTBdL0HXw9SRK/ZcX5zstFabhAfftoz2igqdJ86R4sd2c8CPH 3ph9txhjj5V9gk7c3BzZL3bjw++DKaq/HjngzDt32MJhUzThEADAayfYFsqc/FuIOI 4E5nMyPpTC/8XHkj8n47WgxuODb2AAUhoiKZ6afb4k1L+w8LxoFshlkdm0n1NGrLpH a0YtL/UZjfMM6HR3Os+0F4mVVPAygfF0jNXF0gEcWg5ePIvN0RPPUpNkGjTiskNb9K 595TorqBcwsef4kbS2r4P0d4cY+Lz2sZSVJfKxrSg7DuwOfYxWo107J64CkYuCT9es qGJnunwtwMJRQ== In-Reply-To: <20210913223521.436250-1-sashal-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Nanyong Sun , Ryusuke Konishi , Andrew Morton , Linus Torvalds , Sasha Levin , linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org From: Nanyong Sun [ Upstream commit dbc6e7d44a514f231a64d9d5676e001b660b6448 ] In nilfs_##name##_attr_release, kobj->parent should not be referenced because it is a NULL pointer. The release() method of kobject is always called in kobject_put(kobj), in the implementation of kobject_put(), the kobj->parent will be assigned as NULL before call the release() method. So just use kobj to get the subgroups, which is more efficient and can fix a NULL pointer reference problem. Link: https://lkml.kernel.org/r/20210629022556.3985106-3-sunnanyong-hv44wF8Li93QT0dZR+AlfA@public.gmane.org Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Signed-off-by: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/nilfs2/sysfs.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c index cbfc132206e8..ca720d958315 100644 --- a/fs/nilfs2/sysfs.c +++ b/fs/nilfs2/sysfs.c @@ -64,11 +64,9 @@ static const struct sysfs_ops nilfs_##name##_attr_ops = { \ #define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \ static void nilfs_##name##_attr_release(struct kobject *kobj) \ { \ - struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \ - struct the_nilfs *nilfs = container_of(kobj->parent, \ - struct the_nilfs, \ - ns_##parent_name##_kobj); \ - subgroups = nilfs->ns_##parent_name##_subgroups; \ + struct nilfs_sysfs_##parent_name##_subgroups *subgroups = container_of(kobj, \ + struct nilfs_sysfs_##parent_name##_subgroups, \ + sg_##name##_kobj); \ complete(&subgroups->sg_##name##_kobj_unregister); \ } \ static struct kobj_type nilfs_##name##_ktype = { \ -- 2.30.2