From: James Bottomley <jejb@linux.ibm.com>
To: Colin King <colin.king@canonical.com>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
linux-scsi@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scsi: mvsas: ensure loop counter phy_no does not wrap and cause an infinite loop
Date: Sun, 26 Jan 2020 16:18:24 +0000 [thread overview]
Message-ID: <1580055504.4964.2.camel@linux.ibm.com> (raw)
In-Reply-To: <20200126151747.33320-1-colin.king@canonical.com>
On Sun, 2020-01-26 at 15:17 +0000, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> The loop counter phy_no is a u8 where as the upper limit of the loop
> is a u32. In the event that upper limit is greater than 255 we end
> up with an infinite loop since phy_no will wrap around an never reach
> upper loop limit. Fix this by making phy_no a u32.
This value is limited to MVS_MAX_PHYS (i.e. 8) so I don't see where the
concern comes from. If we were ever to overrun that, we'd corrupt the
chip info structure, because it only allows MVS_MAX_PHYS for the amount
of space.
James
WARNING: multiple messages have this Message-ID (diff)
From: James Bottomley <jejb@linux.ibm.com>
To: Colin King <colin.king@canonical.com>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
linux-scsi@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scsi: mvsas: ensure loop counter phy_no does not wrap and cause an infinite loop
Date: Sun, 26 Jan 2020 08:18:24 -0800 [thread overview]
Message-ID: <1580055504.4964.2.camel@linux.ibm.com> (raw)
In-Reply-To: <20200126151747.33320-1-colin.king@canonical.com>
On Sun, 2020-01-26 at 15:17 +0000, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> The loop counter phy_no is a u8 where as the upper limit of the loop
> is a u32. In the event that upper limit is greater than 255 we end
> up with an infinite loop since phy_no will wrap around an never reach
> upper loop limit. Fix this by making phy_no a u32.
This value is limited to MVS_MAX_PHYS (i.e. 8) so I don't see where the
concern comes from. If we were ever to overrun that, we'd corrupt the
chip info structure, because it only allows MVS_MAX_PHYS for the amount
of space.
James
next prev parent reply other threads:[~2020-01-26 16:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-26 15:17 [PATCH] scsi: mvsas: ensure loop counter phy_no does not wrap and cause an infinite loop Colin King
2020-01-26 15:17 ` Colin King
2020-01-26 16:18 ` James Bottomley [this message]
2020-01-26 16:18 ` James Bottomley
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