Re: [PATCH v2] adfs: validate nzones in adfs_validate_bblk()

[Greg KH <gregkh@linuxfoundation.org>]

On Sat, Mar 21, 2026 at 12:52:13AM +0900, paeyz wrote:
> From: Bae Yeonju <iwasbaeyz@gmail.com>
> 
> Reject ADFS disc records with a zero zone count during boot block
> validation, before the disc record is used.
> 
> When nzones is 0, adfs_read_map() passes it to kmalloc_array(0, ...)
> which returns ZERO_SIZE_PTR, and adfs_map_layout() then writes to
> dm[-1], causing an out-of-bounds write before the allocated buffer.
> 
> adfs_validate_dr0() already rejects nzones != 1 for old-format
> images.  Add the equivalent check to adfs_validate_bblk() for
> new-format images so that a crafted image with nzones == 0 is
> rejected at probe time.
> 
> Found by syzkaller.
> 
> Fixes: f6f14a0d71b0 ("fs/adfs: map: move map-specific sb initialisation to map.c")
> Tested-by: Bae Yeonju <iwasbaeyz@gmail.com>
> Signed-off-by: Bae Yeonju <iwasbaeyz@gmail.com>

Nit, no need for Tested-by if you sign off on the change :)

> ---
>  fs/adfs/super.c | 3 +++
>  1 file changed, 3 insertions(+)

The version info from what changed goes below the --- line.

Anyway, who takes adfs changes these days?  Russell do you?  There's no
MAINTAINERS entry that I can find.  If no one else, I can take it
through one of my trees.

thanks,

greg k-h