Messages in this thread | | | Date | Mon, 12 Sep 2022 08:39:38 -0700 | From | Jaegeuk Kim <> | Subject | Re: [PATCH v2] f2fs: fix to disallow getting inner inode via f2fs_iget() |
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On 09/08, Chao Yu wrote: > On 2022/9/8 10:19, Jaegeuk Kim wrote: > > On 09/08, Chao Yu wrote: > > > On 2022/9/8 10:02, Jaegeuk Kim wrote: > > > > On 08/31, Chao Yu wrote: > > > > > From: Chao Yu <chao.yu@oppo.com> > > > > > > > > > > Introduce f2fs_iget_inner() for f2fs_fill_super() to get inner inode: > > > > > meta inode, node inode or compressed inode, and add f2fs_check_nid_range() > > > > > in f2fs_iget() to avoid getting inner inode from external interfaces. > > > > > > > > So, we don't want to check the range of inner inode numbers? What'd be the > > > > way to check it's okay? > > > > > > For node_ino, meta_ino, root_ino, we have checked them in sanity_check_raw_super() > > > as below: > > > > > > /* check reserved ino info */ > > > if (le32_to_cpu(raw_super->node_ino) != 1 || > > > le32_to_cpu(raw_super->meta_ino) != 2 || > > > le32_to_cpu(raw_super->root_ino) != 3) { > > > f2fs_info(sbi, "Invalid Fs Meta Ino: node(%u) meta(%u) root(%u)", > > > le32_to_cpu(raw_super->node_ino), > > > le32_to_cpu(raw_super->meta_ino), > > > le32_to_cpu(raw_super->root_ino)); > > > return -EFSCORRUPTED; > > > } > > > > > > compressed_ino should always be NM_I(sbi)->max_nid, it can be checked in > > > f2fs_init_compress_inode()? > > > > Hmm, I'm not sure whether we really need this patch, since it'd look better > > to handle all the iget with single f2fs_iget? > > Well, the main concern is previously f2fs_iget() won't check validation for inner > inode due to it will skip do_read_inode() - f2fs_check_nid_range(), so that in a > fuzzed image, caller may pass inner ino into f2fs_iget(), result in incorrect use > of inner inode. So I add f2fs_check_nid_range() in prior to f2fs_iget_inner() in > f2fs_iget() as below to detect and avoid this case.
FWIW, sanity_check_raw_super() checked the inode numbers.
> > > > > > +struct inode *f2fs_iget(struct super_block *sb, unsigned long ino) > > > > > +{ > > > > > + int ret; > > > > > + > > > > > + ret = f2fs_check_nid_range(F2FS_SB(sb), ino); > > > > > + if (ret) > > > > > + return ERR_PTR(ret); > > > > > + > > > > > + return f2fs_iget_inner(sb, ino);
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