From: Andrea Mayer <andrea.mayer@uniroma2.it>
To: Colin King <colin.king@canonical.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
Jakub Kicinski <kuba@kernel.org>,
netdev@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org,
Stefano Salsano <stefano.salsano@uniroma2.it>,
Paolo Lungaroni <paolo.lungaroni@cnit.it>,
Ahmed Abdelsalam <ahabdels.dev@gmail.com>,
Andrea Mayer <andrea.mayer@uniroma2.it>
Subject: Re: [PATCH][next] seg6: fix unintentional integer overflow on left shift
Date: Mon, 7 Dec 2020 20:59:26 +0100 [thread overview]
Message-ID: <20201207205926.6222eca38744c43632248a41@uniroma2.it> (raw)
In-Reply-To: <20201207144503.169679-1-colin.king@canonical.com>
On Mon, 7 Dec 2020 14:45:03 +0000
Colin King <colin.king@canonical.com> wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> Shifting the integer value 1 is evaluated using 32-bit arithmetic
> and then used in an expression that expects a unsigned long value
> leads to a potential integer overflow. Fix this by using the BIT
> macro to perform the shift to avoid the overflow.
>
> Addresses-Coverity: ("Uninitentional integer overflow")
> Fixes: 964adce526a4 ("seg6: improve management of behavior attributes")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> net/ipv6/seg6_local.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
> index b07f7c1c82a4..d68de8cd1207 100644
> --- a/net/ipv6/seg6_local.c
> +++ b/net/ipv6/seg6_local.c
> @@ -1366,7 +1366,7 @@ static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed,
> * attribute; otherwise, we call the destroy() callback.
> */
> for (i = 0; i < max_parsed; ++i) {
> - if (!(parsed_attrs & (1 << i)))
> + if (!(parsed_attrs & BIT(i)))
> continue;
>
> param = &seg6_action_params[i];
> --
> 2.29.2
>
Hi Colin,
thanks for the fix. I've just given a look a the whole seg6_local.c code and I
found that such issues is present in other parts of the code.
If we agree, I can make a fix which explicitly eliminates the several (1 << i)
in favor of BIT(i).
Andrea
next prev parent reply other threads:[~2020-12-07 20:01 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-07 14:45 [PATCH][next] seg6: fix unintentional integer overflow on left shift Colin King
2020-12-07 19:59 ` Andrea Mayer [this message]
2020-12-07 20:44 ` Colin Ian King
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