2020-04-28 05:07:43

by Tianjia Zhang

[permalink] [raw]
Subject: [PATCH v2] module: Allow to disable modsign in kernel cmdline

This option allows to disable modsign completely at the beginning,
and turn off by set the kernel cmdline `no_modsig_enforce` when
`CONFIG_MODULE_SIG_FORCE` is enabled.

Yet another change allows to always show the current status of
modsign through `/sys/module/module/parameters/sig_enforce`.

Signed-off-by: Jia Zhang <[email protected]>
Signed-off-by: Tianjia Zhang <[email protected]>
---
Documentation/admin-guide/kernel-parameters.txt | 6 ++++++
kernel/module.c | 8 ++++++++
2 files changed, 14 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 7bc83f3d9bdf..00ed7566959f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3190,6 +3190,12 @@
noirqdebug [X86-32] Disables the code which attempts to detect and
disable unhandled interrupt sources.

+ no_modsig_enforce
+ [KNL] When CONFIG_MODULE_SIG_FORCE is set, this option
+ allows to disable modsign completely at the beginning.
+ This means that modules without (valid) signatures will
+ success to load.
+
no_timer_check [X86,APIC] Disables the code which tests for
broken timer IRQ sources.

diff --git a/kernel/module.c b/kernel/module.c
index 646f1e2330d2..0e68e1286377 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -269,6 +269,14 @@ static void module_assert_mutex_or_preempt(void)

static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
module_param(sig_enforce, bool_enable_only, 0644);
+#ifdef CONFIG_MODULE_SIG_FORCE
+static int __init set_no_modsig_enforce(char *str)
+{
+ sig_enforce = false;
+ return 1;
+}
+__setup("no_modsig_enforce", set_no_modsig_enforce);
+#endif /* !CONFIG_MODULE_SIG_FORCE */

/*
* Export sig_enforce kernel cmdline parameter to allow other subsystems rely
--
2.17.1


2020-04-28 05:56:03

by Randy Dunlap

[permalink] [raw]
Subject: Re: [PATCH v2] module: Allow to disable modsign in kernel cmdline

Hi,

On 4/27/20 10:05 PM, Tianjia Zhang wrote:
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 7bc83f3d9bdf..00ed7566959f 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -3190,6 +3190,12 @@
> noirqdebug [X86-32] Disables the code which attempts to detect and
> disable unhandled interrupt sources.
>
> + no_modsig_enforce
> + [KNL] When CONFIG_MODULE_SIG_FORCE is set, this option
> + allows to disable modsign completely at the beginning.
> + This means that modules without (valid) signatures will
> + success to load.

succeed to load.

succeed in loading.

load successfully.
I prefer this one..... ^^^^^^^^^^^^^^^^^^^^^

be loaded successfully.


> +
> no_timer_check [X86,APIC] Disables the code which tests for
> broken timer IRQ sources.
>

thanks.
--
~Randy

2020-04-28 06:05:46

by Tianjia Zhang

[permalink] [raw]
Subject: Re: [PATCH v2] module: Allow to disable modsign in kernel cmdline



On 2020/4/28 13:52, Randy Dunlap wrote:
> Hi,
>
> On 4/27/20 10:05 PM, Tianjia Zhang wrote:
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
>> index 7bc83f3d9bdf..00ed7566959f 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -3190,6 +3190,12 @@
>> noirqdebug [X86-32] Disables the code which attempts to detect and
>> disable unhandled interrupt sources.
>>
>> + no_modsig_enforce
>> + [KNL] When CONFIG_MODULE_SIG_FORCE is set, this option
>> + allows to disable modsign completely at the beginning.
>> + This means that modules without (valid) signatures will
>> + success to load.
>
> succeed to load.
>
> succeed in loading.
>
> load successfully.
> I prefer this one..... ^^^^^^^^^^^^^^^^^^^^^
>
> be loaded successfully.
>
>
>> +
>> no_timer_check [X86,APIC] Disables the code which tests for
>> broken timer IRQ sources.
>>
>
> thanks.
>

v3 patch has been submitted, thank you for your suggestion.

Thanks,
Tianjia