From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Colin King <colin.king@canonical.com>
Cc: Len Brown <lenb@kernel.org>,
linux-acpi@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ACPI / CPPC: remove initial assignment of pcc_ss_data
Date: Sat, 16 Dec 2017 02:49:02 +0100 [thread overview]
Message-ID: <3514960.SrIDOzrZqR@aspire.rjw.lan> (raw)
In-Reply-To: <20171208235949.15713-1-colin.king@canonical.com>
On Saturday, December 9, 2017 12:59:49 AM CET Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> The initialization of pcc_ss_data from pcc_data[pcc_ss_id] before
> pcc_ss_id is being range checked could lead to an out-of-bounds array
> read. This very same initialization is also being performed after
> the range check on pcc_ss_id, so we can just remove this problematic
> and also redundant assignment to fix the issue.
>
> Detected by cppcheck:
> warning: Value stored to 'pcc_ss_data' during its initialization is never
> read
>
> Fixes: commit 85b1407bf6d2 ("ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> drivers/acpi/cppc_acpi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index 30e84cc600ae..06ea4749ebd9 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -1171,7 +1171,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
> struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
> struct cpc_register_resource *desired_reg;
> int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
> - struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
> + struct cppc_pcc_data *pcc_ss_data;
> int ret = 0;
>
> if (!cpc_desc || pcc_ss_id < 0) {
>
Applied, thanks!
prev parent reply other threads:[~2017-12-16 1:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-08 23:59 [PATCH] ACPI / CPPC: remove initial assignment of pcc_ss_data Colin King
2017-12-16 1:49 ` Rafael J. Wysocki [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3514960.SrIDOzrZqR@aspire.rjw.lan \
--to=rjw@rjwysocki.net \
--cc=colin.king@canonical.com \
--cc=kernel-janitors@vger.kernel.org \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).