[PATCH 3/3] SELinux: add selinux_kernel_module_request

From: Eric Paris
Date: Thu Aug 13 2009 - 09:47:07 EST


This patch adds a new selinux hook so SELinux can arbitrate if a given
process should be allowed to trigger a request for the kernel to try to
load a module. This is a different operation than a process trying to load
a module itself, which is already protected by CAP_SYS_MODULE.

Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
---

security/selinux/hooks.c | 6 ++++++
security/selinux/include/av_perm_to_string.h | 1 +
security/selinux/include/av_permissions.h | 1 +
3 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 38afca9..b0d72f1 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3296,6 +3296,11 @@ static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
return 0;
}

+static int selinux_kernel_module_request(void)
+{
+ return task_has_system(current, SYSTEM__MODULE_REQUEST);
+}
+
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
return current_has_perm(p, PROCESS__SETPGID);
@@ -5457,6 +5462,7 @@ static struct security_operations selinux_ops = {
.cred_prepare = selinux_cred_prepare,
.kernel_act_as = selinux_kernel_act_as,
.kernel_create_files_as = selinux_kernel_create_files_as,
+ .kernel_module_request = selinux_kernel_module_request,
.task_setpgid = selinux_task_setpgid,
.task_getpgid = selinux_task_getpgid,
.task_getsid = selinux_task_getsid,
diff --git a/security/selinux/include/av_perm_to_string.h b/security/selinux/include/av_perm_to_string.h
index 31df1d7..2b683ad 100644
--- a/security/selinux/include/av_perm_to_string.h
+++ b/security/selinux/include/av_perm_to_string.h
@@ -107,6 +107,7 @@
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, "syslog_read")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, "syslog_mod")
S_(SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, "syslog_console")
+ S_(SECCLASS_SYSTEM, SYSTEM__MODULE_REQUEST, "module_request")
S_(SECCLASS_CAPABILITY, CAPABILITY__CHOWN, "chown")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_OVERRIDE, "dac_override")
S_(SECCLASS_CAPABILITY, CAPABILITY__DAC_READ_SEARCH, "dac_read_search")
diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h
index 0b41ad5..0546d61 100644
--- a/security/selinux/include/av_permissions.h
+++ b/security/selinux/include/av_permissions.h
@@ -530,6 +530,7 @@
#define SYSTEM__SYSLOG_READ 0x00000002UL
#define SYSTEM__SYSLOG_MOD 0x00000004UL
#define SYSTEM__SYSLOG_CONSOLE 0x00000008UL
+#define SYSTEM__MODULE_REQUEST 0x00000010UL
#define CAPABILITY__CHOWN 0x00000001UL
#define CAPABILITY__DAC_OVERRIDE 0x00000002UL
#define CAPABILITY__DAC_READ_SEARCH 0x00000004UL

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