Re: [PATCH 3/3] SELinux: add selinux_kernel_module_request

From: Serge E. Hallyn
Date: Thu Aug 13 2009 - 14:44:13 EST


Quoting Eric Paris (eparis@xxxxxxxxxx):
> 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>

Acked-by: Serge Hallyn <serue@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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