Re: [f2fs-dev] [PATCH v2] f2fs: fix to disallow getting inner inode via f2fs_iget()

[Chao Yu]

On 2022/9/8 10:02, Jaegeuk Kim wrote:

On 08/31, Chao Yu wrote:

From: Chao Yu <chao...@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()?

Thanks,

Signed-off-by: Chao Yu <chao...@oppo.com>
---
v2:
- don't override errno from f2fs_check_nid_range()
- fix compile error
  fs/f2fs/compress.c |  2 +-
  fs/f2fs/f2fs.h     |  1 +
  fs/f2fs/inode.c    | 13 ++++++++++++-
  fs/f2fs/super.c    |  4 ++--
  4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 730256732a9e..c38b22bb6432 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1947,7 +1947,7 @@ int f2fs_init_compress_inode(struct f2fs_sb_info *sbi)
        if (!test_opt(sbi, COMPRESS_CACHE))
                return 0;

- inode = f2fs_iget(sbi->sb, F2FS_COMPRESS_INO(sbi));

+       inode = f2fs_iget_inner(sbi->sb, F2FS_COMPRESS_INO(sbi));
        if (IS_ERR(inode))
                return PTR_ERR(inode);
        sbi->compress_inode = inode;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 408d8034ed74..35f9e1a6a1bf 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3467,6 +3467,7 @@ int f2fs_pin_file_control(struct inode *inode, bool inc);
  void f2fs_set_inode_flags(struct inode *inode);
  bool f2fs_inode_chksum_verify(struct f2fs_sb_info *sbi, struct page *page);
  void f2fs_inode_chksum_set(struct f2fs_sb_info *sbi, struct page *page);
+struct inode *f2fs_iget_inner(struct super_block *sb, unsigned long ino);
  struct inode *f2fs_iget(struct super_block *sb, unsigned long ino);
  struct inode *f2fs_iget_retry(struct super_block *sb, unsigned long ino);
  int f2fs_try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 6d11c365d7b4..965f87c1dd63 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -480,7 +480,7 @@ static int do_read_inode(struct inode *inode)
        return 0;
  }

-struct inode *f2fs_iget(struct super_block *sb, unsigned long ino)

+struct inode *f2fs_iget_inner(struct super_block *sb, unsigned long ino)
  {
        struct f2fs_sb_info *sbi = F2FS_SB(sb);
        struct inode *inode;
@@ -568,6 +568,17 @@ struct inode *f2fs_iget(struct super_block *sb, unsigned 
long ino)
        return ERR_PTR(ret);
  }

+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);
+}
+
  struct inode *f2fs_iget_retry(struct super_block *sb, unsigned long ino)
  {
        struct inode *inode;
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index b8e5fe244596..a5f5e7483791 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -4157,7 +4157,7 @@ static int f2fs_fill_super(struct super_block *sb, void 
*data, int silent)
                goto free_xattr_cache;

/* get an inode for meta space */

-       sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
+       sbi->meta_inode = f2fs_iget_inner(sb, F2FS_META_INO(sbi));
        if (IS_ERR(sbi->meta_inode)) {
                f2fs_err(sbi, "Failed to read F2FS meta data inode");
                err = PTR_ERR(sbi->meta_inode);
@@ -4265,7 +4265,7 @@ static int f2fs_fill_super(struct super_block *sb, void 
*data, int silent)
                goto free_nm;

/* get an inode for node space */

-       sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi));
+       sbi->node_inode = f2fs_iget_inner(sb, F2FS_NODE_INO(sbi));
        if (IS_ERR(sbi->node_inode)) {
                f2fs_err(sbi, "Failed to read node inode");
                err = PTR_ERR(sbi->node_inode);
--
2.25.1

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