linux-kernel - Re: [PATCH v3] f2fs: fix to detect corrupted meta ino

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Message-ID: <YyylXIEhaearlfEf@google.com>
Date:   Thu, 22 Sep 2022 11:11:40 -0700
From:   Jaegeuk Kim <jaegeuk@...nel.org>
To:     Chao Yu <chao@...nel.org>
Cc:     linux-f2fs-devel@...ts.sourceforge.net,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] f2fs: fix to detect corrupted meta ino

I modified a bit.

https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev-test&id=a9a1592fa175baaaae43f54f175a972757c47919

Thanks,

On 09/22, Chao Yu wrote:
> Ping,
> 
> On 2022/9/13 15:48, Chao Yu wrote:
> > It is possible that ino of dirent or orphan inode is corrupted in a
> > fuzzed image, occasionally, if corrupted ino is equal to meta ino:
> > meta_ino, node_ino or compress_ino, caller of f2fs_iget() from below
> > call paths will get meta inode directly, it's not allowed, let's
> > add sanity check to detect such cases.
> > 
> > case #1
> > - recover_dentry
> >   - __f2fs_find_entry
> >   - f2fs_iget_retry
> > 
> > case #2
> > - recover_orphan_inode
> >   - f2fs_iget_retry
> > 
> > Signed-off-by: Chao Yu <chao@...nel.org>
> > ---
> > v3:
> > - update commit title/message
> > - change logic inside f2fs_iget() rather than its caller
> >   fs/f2fs/inode.c | 25 ++++++++++++++++++-------
> >   1 file changed, 18 insertions(+), 7 deletions(-)
> > 
> > diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
> > index cde0a3dc80c3..1baac6056733 100644
> > --- a/fs/f2fs/inode.c
> > +++ b/fs/f2fs/inode.c
> > @@ -487,6 +487,12 @@ static int do_read_inode(struct inode *inode)
> >   	return 0;
> >   }
> > +static bool is_meta_ino(struct f2fs_sb_info *sbi, unsigned int ino)
> > +{
> > +	return ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi) ||
> > +		ino == F2FS_COMPRESS_INO(sbi);
> > +}
> > +
> >   struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
> >   {
> >   	struct f2fs_sb_info *sbi = F2FS_SB(sb);
> > @@ -497,17 +503,22 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)
> >   	if (!inode)
> >   		return ERR_PTR(-ENOMEM);
> > +	if (is_meta_ino(sbi, ino)) {
> > +		if (!(inode->i_state & I_NEW)) {
> > +			f2fs_err(sbi, "detect corrupted inode no:%lu, run fsck to repair", ino);
> > +			set_sbi_flag(sbi, SBI_NEED_FSCK);
> > +			ret = -EFSCORRUPTED;
> > +			trace_f2fs_iget_exit(inode, ret);
> > +			iput(inode);
> > +			return ERR_PTR(ret);
> > +		}
> > +		goto make_now;
> > +	}
> > +
> >   	if (!(inode->i_state & I_NEW)) {
> >   		trace_f2fs_iget(inode);
> >   		return inode;
> >   	}
> > -	if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi))
> > -		goto make_now;
> > -
> > -#ifdef CONFIG_F2FS_FS_COMPRESSION
> > -	if (ino == F2FS_COMPRESS_INO(sbi))
> > -		goto make_now;
> > -#endif
> >   	ret = do_read_inode(inode);
> >   	if (ret)