Re: [PATCH 4.14] inet: use bigger hash table for IP ID generation (backported to 4.14)

From: Greg KH
Date: Fri Jun 18 2021 - 06:24:44 EST


On Fri, Jun 18, 2021 at 02:51:22AM -0700, Amit Klein wrote:
> Subject: inet: use bigger hash table for IP ID generation (backported to 4.14)
> From: Amit Klein <aksecurity@xxxxxxxxx>
>
> This is a backport to 4.14 of the following patch, originally
> developed by Eric Dumazet.
>
> In commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
> I used a very small hash table that could be abused
> by patient attackers to reveal sensitive information.
>
> Switch to a dynamic sizing, depending on RAM size.
>
> Typical big hosts will now use 128x more storage (2 MB)
> to get a similar increase in security and reduction
> of hash collisions.
>
> As a bonus, use of alloc_large_system_hash() spreads
> allocated memory among all NUMA nodes.
>
> Fixes: 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
> Reported-by: Amit Klein <aksecurity@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Willy Tarreau <w@xxxxxx>
> ---

What is the git commit id of this patch in Linus's tree?

thanks,

greg k-h