From: Justin Stitt <justinstitt@google.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org,
Justin Stitt <justinstitt@google.com>
Subject: [PATCH] cpufreq: refactor deprecated strncpy
Date: Wed, 13 Sep 2023 00:07:21 +0000 [thread overview]
Message-ID: <20230913-strncpy-drivers-cpufreq-cpufreq-c-v1-1-f1608bfeff63@google.com> (raw)
`strncpy` is deprecated for use on NUL-terminated destination strings [1].
We should prefer more robust and less ambiguous string interfaces.
Both `policy->last_governor` and `default_governor` are expected to be
NUL-terminated which is shown by their heavy usage with other string
apis like `strcmp`.
A suitable replacement is `strscpy` [2] due to the fact that it guarantees
NUL-termination on the destination buffer.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested
---
drivers/cpufreq/cpufreq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 50bbc969ffe5..3eb851a03fce 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1607,7 +1607,7 @@ static void __cpufreq_offline(unsigned int cpu, struct cpufreq_policy *policy)
}
if (has_target())
- strncpy(policy->last_governor, policy->governor->name,
+ strscpy(policy->last_governor, policy->governor->name,
CPUFREQ_NAME_LEN);
else
policy->last_policy = policy->policy;
@@ -2951,7 +2951,7 @@ static int __init cpufreq_core_init(void)
BUG_ON(!cpufreq_global_kobject);
if (!strlen(default_governor))
- strncpy(default_governor, gov->name, CPUFREQ_NAME_LEN);
+ strscpy(default_governor, gov->name, CPUFREQ_NAME_LEN);
return 0;
}
---
base-commit: 2dde18cd1d8fac735875f2e4987f11817cc0bc2c
change-id: 20230912-strncpy-drivers-cpufreq-cpufreq-c-1d800044b007
Best regards,
--
Justin Stitt <justinstitt@google.com>
next reply other threads:[~2023-09-13 0:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-13 0:07 Justin Stitt [this message]
2023-09-15 3:37 ` [PATCH] cpufreq: refactor deprecated strncpy Kees Cook
2023-09-28 6:58 ` Viresh Kumar
2023-09-29 18:44 ` Kees Cook
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