From: Christian Brauner <brauner@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: syzbot <syzbot+2faac0423fdc9692822b@syzkaller.appspotmail.com>,
jack@suse.cz, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
viro@zeniv.linux.org.uk
Subject: Re: [syzbot] [fs?] KASAN: slab-use-after-free Read in test_bdev_super_fc
Date: Fri, 4 Aug 2023 17:29:37 +0200 [thread overview]
Message-ID: <20230804-auferlegen-esstisch-fdf67276d18c@brauner> (raw)
In-Reply-To: <20230804-kurvigen-uninteressant-09d451db7458@brauner>
On Fri, Aug 04, 2023 at 04:49:23PM +0200, Christian Brauner wrote:
> On Fri, Aug 04, 2023 at 04:43:43PM +0200, Christoph Hellwig wrote:
> > On Fri, Aug 04, 2023 at 04:36:49PM +0200, Christian Brauner wrote:
> > > FFS
> >
> > Good spot, this explains the missing dropping of s_umount.
> >
> > But I don't think it's doing the right thing for MTD mount romfs,
> > we'll need something like this:
>
> I'll fold a fix into Jan's patch.
Folding:
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index c59b230d55b4..2b9f3e3c052a 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -583,16 +583,20 @@ static int romfs_init_fs_context(struct fs_context *fc)
*/
static void romfs_kill_sb(struct super_block *sb)
{
+ generic_shutdown_super(sb);
+
#ifdef CONFIG_ROMFS_ON_MTD
if (sb->s_mtd) {
- kill_mtd_super(sb);
- return;
+ put_mtd_device(sb->s_mtd);
+ sb->s_mtd = NULL;
}
#endif
#ifdef CONFIG_ROMFS_ON_BLOCK
if (sb->s_bdev) {
- kill_block_super(sb);
- return;
+ sb->s_bdev->bd_super = NULL;
+ sync_blockdev(sb->s_bdev);
+ blkdev_put(sb->s_bdev, sb->s_type);
}
#endif
}
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 27c6597aa1be..0b6cc8a03b54 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -485,12 +485,17 @@ static void cramfs_kill_sb(struct super_block *sb)
{
struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
+ generic_shutdown_super(sb);
+
if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sb->s_mtd) {
if (sbi && sbi->mtd_point_size)
mtd_unpoint(sb->s_mtd, 0, sbi->mtd_point_size);
- kill_mtd_super(sb);
+ put_mtd_device(sb->s_mtd);
+ sb->s_mtd = NULL;
} else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV) && sb->s_bdev) {
- kill_block_super(sb);
+ sb->s_bdev->bd_super = NULL;
+ sync_blockdev(sb->s_bdev);
+ blkdev_put(sb->s_bdev, sb->s_type);
}
kfree(sbi);
}
next prev parent reply other threads:[~2023-08-04 15:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-03 22:14 [syzbot] [fs?] KASAN: slab-use-after-free Read in test_bdev_super_fc syzbot
2023-08-04 10:14 ` Christoph Hellwig
2023-08-04 13:20 ` Christian Brauner
2023-08-04 14:02 ` Christoph Hellwig
2023-08-04 14:36 ` Christian Brauner
2023-08-04 14:43 ` Christoph Hellwig
2023-08-04 14:49 ` Christian Brauner
2023-08-04 15:29 ` Christian Brauner [this message]
2023-08-05 8:57 ` Christoph Hellwig
[not found] ` <20230805084316.1699-1-hdanton@sina.com>
2023-08-05 8:48 ` Christoph Hellwig
[not found] <20230804125406.1583-1-hdanton@sina.com>
2023-08-04 19:13 ` syzbot
[not found] <20230804233428.1642-1-hdanton@sina.com>
2023-08-05 0:11 ` syzbot
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