Re: [PATCH v2] exfat: combine iocharset and utf8 option setup

[Namjae Jeon <linkinjeon@kernel.org>]

On Sun, Sep 28, 2025 at 11:04 AM Yuezhang.Mo@sony.com
<Yuezhang.Mo@sony.com> wrote:
>
> On Sat, 27 Sep 2025 00:35:22 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> > Currently, exfat utf8 mount option depends on the iocharset option
> > value. After exfat remount, utf8 option may become inconsistent with
> > iocharset option.
> >
> > If the options are inconsistent; (specifically, iocharset=utf8 but
> > utf8=0) readdir may reference uninitalized NLS, leading to a null
> > pointer dereference.
> >
> > Extract and combine utf8/iocharset setup logic into exfat_set_iocharset().
> > Then Replace iocharset setup logic to exfat_set_iocharset to prevent
> > utf8/iocharset option inconsistentcy after remount.
> >
> > Reported-by: syzbot+3e9cb93e3c5f90d28e19@syzkaller.appspotmail.com
> > Closes: https://syzkaller.appspot.com/bug?extid=3e9cb93e3c5f90d28e19
> > Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
> > Fixes: acab02ffcd6b ("exfat: support modifying mount options via remount")
> > Tested-by: syzbot+3e9cb93e3c5f90d28e19@syzkaller.appspotmail.com
> > ---
> > Changes from v1 [1]
> > - extract utf8/iocharset setup logic to tiny function
> > - apply utf8/iocharset setup to exfat_init_fs_context()
> >
> > [1] https://lore.kernel.org/all/20250925184040.692919-1-ekffu200098@gmail.com/
>
> Looks good to me.
> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Applied it to #dev.
Thanks!