Re: [PATCH] jfs: validate max amount of blocks before allocation.

Greg KH
2023-07-22T15:16:36Z

On Sat, Jul 22, 2023 at 05:24:01PM +0300, Aleksei Filippov wrote:
> From: Alexei Filippov <halip0503@gmail.com>
>
> The lack of checking bmp->db_max_freebud in extBalloc() can lead to
> shift out of bounds, so this patch prevents undefined behavior,
> because bmp->db_max_freebud == -1 only if there
> is no free space.

Please wrap at 72 columns properly.

>
> Signed-off-by: Aleksei Filippov <halip0503@gmail.com>
> Reported-and-tested-by: syzbot+5f088f29593e6b4c8db8@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?id=01abadbd6ae6a08b1f1987aa61554c6b3ac19ff2
> ---
> fs/jfs/jfs_extent.c | 5 +++++
> 1 file changed, 5 insertions(+)

What commit id does this fix?

Is it needed for stable kernels? If so, please tag it as such.

thanks,

greg k-h