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

Chao Yu
2022-09-22T01:54:28Z

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@kernel.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)