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

[Chao Yu]

On 2022/9/23 2:11, Jaegeuk Kim wrote:
> I modified a bit.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev-test&id=a9a1592fa175baaaae43f54f175a972757c47919

Fine to me. :)

Thanks,

> 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@xxxxxxxxxx>
> > > ---
> > > 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)