lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:   Tue, 26 May 2020 00:19:29 +0200
From:   Daniel Borkmann <>
To:     Björn Töpel <>,,,,,
Cc:     Björn Töpel <>,,
        Minh Bùi Quang <>
Subject: Re: [PATCH bpf] xsk: add overflow check for u64 division, stored into

On 5/25/20 10:03 AM, Björn Töpel wrote:
> From: Björn Töpel <>
> The npgs member of struct xdp_umem is an u32 entity, and stores the
> number of pages the UMEM consumes. The calculation of npgs
>    npgs = size / PAGE_SIZE
> can overflow.
> To avoid overflow scenarios, the division is now first stored in a
> u64, and the result is verified to fit into 32b.
> An alternative would be storing the npgs as a u64, however, this
> wastes memory and is an unrealisticly large packet area.
> Link:
> Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt")
> Reported-by: "Minh Bùi Quang" <>
> Signed-off-by: Björn Töpel <>

Applied, thanks!

Powered by blists - more mailing lists