linux-kernel - Re: [PATCH] ALSA: xen-front: fix unintention integer overflow on left shifts

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 for Android: free password hash cracker in your pocket

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

Message-ID: <s5hv9wq6qrg.wl-tiwai@suse.de>
Date:   Fri, 28 Jun 2019 10:46:59 +0200
From:   Takashi Iwai <tiwai@...e.de>
To:     "Colin King" <colin.king@...onical.com>
Cc:     <alsa-devel@...a-project.org>,
        "Oleksandr Andrushchenko" <oleksandr_andrushchenko@...m.com>,
        <xen-devel@...ts.xenproject.org>,
        "Jaroslav Kysela" <perex@...ex.cz>,
        <kernel-janitors@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ALSA: xen-front: fix unintention integer overflow on left shifts

On Thu, 27 Jun 2019 18:58:53 +0200,
Colin King wrote:
> 
> From: Colin Ian King <colin.king@...onical.com>
> 
> Shifting the integer value 1 is evaluated using 32-bit
> arithmetic and then used in an expression that expects a 64-bit
> value, so there is potentially an integer overflow. Fix this
> by using the BIT_ULL macro to perform the shift.
> 
> Addresses-Coverity: ("Unintentional integer overflow")
> Signed-off-by: Colin Ian King <colin.king@...onical.com>

The fix is correct, but luckily we didn't hit the integer overflow, as
all passed values are less than 32bit.

In anyway, applied now.  Thanks.


Takashi

> ---
>  sound/xen/xen_snd_front_alsa.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/xen/xen_snd_front_alsa.c b/sound/xen/xen_snd_front_alsa.c
> index b14ab512c2ce..e01631959ed8 100644
> --- a/sound/xen/xen_snd_front_alsa.c
> +++ b/sound/xen/xen_snd_front_alsa.c
> @@ -196,7 +196,7 @@ static u64 to_sndif_formats_mask(u64 alsa_formats)
>  	mask = 0;
>  	for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
>  		if (pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa) & alsa_formats)
> -			mask |= 1 << ALSA_SNDIF_FORMATS[i].sndif;
> +			mask |= BIT_ULL(ALSA_SNDIF_FORMATS[i].sndif);
>  
>  	return mask;
>  }
> @@ -208,7 +208,7 @@ static u64 to_alsa_formats_mask(u64 sndif_formats)
>  
>  	mask = 0;
>  	for (i = 0; i < ARRAY_SIZE(ALSA_SNDIF_FORMATS); i++)
> -		if (1 << ALSA_SNDIF_FORMATS[i].sndif & sndif_formats)
> +		if (BIT_ULL(ALSA_SNDIF_FORMATS[i].sndif) & sndif_formats)
>  			mask |= pcm_format_to_bits(ALSA_SNDIF_FORMATS[i].alsa);
>  
>  	return mask;
> -- 
> 2.20.1
> 
>