Re: [PATCH] f2fs: initialize ino_entry_info before checkpoint load

[Chao Yu]

On 5/9/26 12:22, Deepanshu Kartikey wrote:
> When f2fs_get_valid_checkpoint() fails during mount (e.g. due to an
> invalid checkpoint CRC on a malformed image), f2fs_fill_super() takes
> an error path that eventually calls iput() on the root inode. This
> invokes f2fs_drop_inode() -> f2fs_exist_written_data(), which acquires
> sbi->im[]->ino_lock. However, f2fs_init_ino_entry_info() has not run
> yet at this point, so the spinlock is uninitialized and lockdep
> complains:
>
>    F2FS-fs (loop0): invalid crc value
>    F2FS-fs (loop0): Failed to get valid F2FS checkpoint
>    INFO: trying to register non-static key.
>    The code is fine but needs lockdep annotation, or maybe
>    you didn't initialize this object before use?
>    ...
>     f2fs_exist_written_data+0x53/0x90 fs/f2fs/checkpoint.c:787
>     f2fs_drop_inode+0xda/0xbf0 fs/f2fs/super.c:1852
>     iput+0x651/0xe80 fs/inode.c:2009
>     f2fs_fill_super+0x6047/0x7850 fs/f2fs/super.c:5461
>
> Move f2fs_init_ino_entry_info() to before f2fs_get_valid_checkpoint()
> so that sbi->im[] is always fully initialized before any error path
> can trigger iput() -> f2fs_drop_inode(). The init function only
> depends on raw superblock fields (BLKS_PER_SEG, F2FS_CP_PACKS,
> NR_CURSEG_PERSIST_TYPE, __cp_payload), which are populated well
> before checkpoint load, so the move is safe.

Cc: stable@xxxxxxxxxx
Fixes: xxx

Otherwise, it looks good to me.

Thanks,

> Reported-by: syzbot+eec8f2693d71386bd600@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://syzkaller.appspot.com/bug?extid=eec8f2693d71386bd600
> Tested-by: syzbot+eec8f2693d71386bd600@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Deepanshu Kartikey <kartikey406@xxxxxxxxx>
> ---
>   fs/f2fs/super.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index c6afdbd6e1cd..6a231a5b0d62 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -5140,6 +5140,13 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
>   		goto free_page_array_cache;
>   	}
>   
> +	/*
> +	 * Initialize ino entry info early so f2fs_drop_inode ->
> +	 * f2fs_exist_written_data can safely take im->ino_lock if mount
> +	 * fails after this point and triggers iput on cleanup.
> +	 */
> +	f2fs_init_ino_entry_info(sbi);
> +
>   	err = f2fs_get_valid_checkpoint(sbi);
>   	if (err) {
>   		f2fs_err(sbi, "Failed to get valid F2FS checkpoint");
> @@ -5184,8 +5191,6 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc)
>   
>   	f2fs_init_extent_cache_info(sbi);
>   
> -	f2fs_init_ino_entry_info(sbi);
> -
>   	f2fs_init_fsync_node_info(sbi);
>   
>   	/* setup checkpoint request control and start checkpoint issue thread */