module: limit enabling module.sig_enforce

[ Upstream commit 0c18f29aae7ce3dadd26d8ee3505d07cc982df75 ]

Irrespective as to whether CONFIG_MODULE_SIG is configured, specifying
"module.sig_enforce=1" on the boot command line sets "sig_enforce".
Only allow "sig_enforce" to be set when CONFIG_MODULE_SIG is configured.

This patch makes the presence of /sys/module/module/parameters/sig_enforce
dependent on CONFIG_MODULE_SIG=y.

Fixes: fda784e50a ("module: export module signature enforcement status")
Reported-by: Nayna Jain <nayna@linux.ibm.com>
Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Tested-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Mimi Zohar 2021-06-22 13:36:41 +02:00 committed by Sasha Levin
parent 4037804c55
commit e2dc07ca4e
1 changed files with 9 additions and 5 deletions

View File

@ -268,9 +268,18 @@ static void module_assert_mutex_or_preempt(void)
#endif
}
#ifdef CONFIG_MODULE_SIG
static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
module_param(sig_enforce, bool_enable_only, 0644);
void set_module_sig_enforced(void)
{
sig_enforce = true;
}
#else
#define sig_enforce false
#endif
/*
* Export sig_enforce kernel cmdline parameter to allow other subsystems rely
* on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
@ -281,11 +290,6 @@ bool is_module_sig_enforced(void)
}
EXPORT_SYMBOL(is_module_sig_enforced);
void set_module_sig_enforced(void)
{
sig_enforce = true;
}
/* Block module loading/unloading? */
int modules_disabled = 0;
core_param(nomodule, modules_disabled, bint, 0);