linux-kernel - Re: [PATCH] tcp_nv: fix potential integer overflow in tcpnv

lists.openwall.net		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 linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-Id: <20180131.103300.1736696032660575093.davem@davemloft.net>
Date:   Wed, 31 Jan 2018 10:33:00 -0500 (EST)
From:   David Miller <davem@...emloft.net>
To:     gustavo@...eddedor.com
Cc:     kuznet@....inr.ac.ru, yoshfuji@...ux-ipv6.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        garsilva@...eddedor.com
Subject: Re: [PATCH] tcp_nv: fix potential integer overflow in tcpnv_acked

From: "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Date: Tue, 30 Jan 2018 22:21:48 -0600

> Add suffix ULL to constant 80000 in order to avoid a potential integer
> overflow and give the compiler complete information about the proper
> arithmetic to use. Notice that this constant is used in a context that
> expects an expression of type u64.
> 
> The current cast to u64 effectively applies to the whole expression
> as an argument of type u64 to be passed to div64_u64, but it does
> not prevent it from being evaluated using 32-bit arithmetic instead
> of 64-bit arithmetic.
> 
> Also, once the expression is properly evaluated using 64-bit arithmentic,
> there is no need for the parentheses and the external cast to u64.
> 
> Addresses-Coverity-ID: 1357588 ("Unintentional integer overflow")
> Signed-off-by: Gustavo A. R. Silva <gustavo@...eddedor.com>

Applied.