aboutsummaryrefslogtreecommitdiffstats
path: root/security/selinux
diff options
context:
space:
mode:
Diffstat (limited to 'security/selinux')
-rw-r--r--security/selinux/include/security.h21
-rw-r--r--security/selinux/selinuxfs.c56
-rw-r--r--security/selinux/ss/Makefile2
-rw-r--r--security/selinux/ss/services.c3
-rw-r--r--security/selinux/ss/status.c129
5 files changed, 210 insertions, 1 deletions
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 1f7c2491d3d..e390e31bb4b 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -191,5 +191,26 @@ static inline int security_netlbl_sid_to_secattr(u32 sid,
const char *security_get_initial_sid_context(u32 sid);
+/*
+ * status notifier using mmap interface
+ */
+extern struct page *selinux_kernel_status_page(void);
+
+#define SELINUX_KERNEL_STATUS_VERSION 1
+struct selinux_kernel_status
+{
+ u32 version; /* version number of thie structure */
+ u32 sequence; /* sequence number of seqlock logic */
+ u32 enforcing; /* current setting of enforcing mode */
+ u32 policyload; /* times of policy reloaded */
+ u32 deny_unknown; /* current setting of deny_unknown */
+ /*
+ * The version > 0 supports above members.
+ */
+} __attribute__((packed));
+
+extern void selinux_status_update_setenforce(int enforcing);
+extern void selinux_status_update_policyload(int seqno);
+
#endif /* _SELINUX_SECURITY_H_ */
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 79a1bb63566..a2e7a8563b3 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -110,6 +110,7 @@ enum sel_inos {
SEL_COMPAT_NET, /* whether to use old compat network packet controls */
SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
+ SEL_STATUS, /* export current status using mmap() */
SEL_INO_NEXT, /* The next inode number to use */
};
@@ -171,6 +172,7 @@ static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
if (selinux_enforcing)
avc_ss_reset(0);
selnl_notify_setenforce(selinux_enforcing);
+ selinux_status_update_setenforce(selinux_enforcing);
}
length = count;
out:
@@ -205,6 +207,59 @@ static const struct file_operations sel_handle_unknown_ops = {
.llseek = generic_file_llseek,
};
+static int sel_open_handle_status(struct inode *inode, struct file *filp)
+{
+ struct page *status = selinux_kernel_status_page();
+
+ if (!status)
+ return -ENOMEM;
+
+ filp->private_data = status;
+
+ return 0;
+}
+
+static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct page *status = filp->private_data;
+
+ BUG_ON(!status);
+
+ return simple_read_from_buffer(buf, count, ppos,
+ page_address(status),
+ sizeof(struct selinux_kernel_status));
+}
+
+static int sel_mmap_handle_status(struct file *filp,
+ struct vm_area_struct *vma)
+{
+ struct page *status = filp->private_data;
+ unsigned long size = vma->vm_end - vma->vm_start;
+
+ BUG_ON(!status);
+
+ /* only allows one page from the head */
+ if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
+ return -EIO;
+ /* disallow writable mapping */
+ if (vma->vm_flags & VM_WRITE)
+ return -EPERM;
+ /* disallow mprotect() turns it into writable */
+ vma->vm_flags &= ~VM_MAYWRITE;
+
+ return remap_pfn_range(vma, vma->vm_start,
+ page_to_pfn(status),
+ size, vma->vm_page_prot);
+}
+
+static const struct file_operations sel_handle_status_ops = {
+ .open = sel_open_handle_status,
+ .read = sel_read_handle_status,
+ .mmap = sel_mmap_handle_status,
+ .llseek = generic_file_llseek,
+};
+
#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static ssize_t sel_write_disable(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
@@ -1612,6 +1667,7 @@ static int sel_fill_super(struct super_block *sb, void *data, int silent)
[SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
[SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
[SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
+ [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
/* last one */ {""}
};
ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
diff --git a/security/selinux/ss/Makefile b/security/selinux/ss/Makefile
index 15d4e62917d..974e11c7cf5 100644
--- a/security/selinux/ss/Makefile
+++ b/security/selinux/ss/Makefile
@@ -5,5 +5,5 @@
EXTRA_CFLAGS += -Isecurity/selinux -Isecurity/selinux/include
obj-y := ss.o
-ss-y := ebitmap.o hashtab.o symtab.o sidtab.o avtab.o policydb.o services.o conditional.o mls.o
+ss-y := ebitmap.o hashtab.o symtab.o sidtab.o avtab.o policydb.o services.o conditional.o mls.o status.o
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 9ea2feca3cd..494ff527c17 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1791,6 +1791,7 @@ int security_load_policy(void *data, size_t len)
selinux_complete_init();
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
+ selinux_status_update_policyload(seqno);
selinux_netlbl_cache_invalidate();
selinux_xfrm_notify_policyload();
return 0;
@@ -1870,6 +1871,7 @@ int security_load_policy(void *data, size_t len)
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
+ selinux_status_update_policyload(seqno);
selinux_netlbl_cache_invalidate();
selinux_xfrm_notify_policyload();
@@ -2374,6 +2376,7 @@ out:
if (!rc) {
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
+ selinux_status_update_policyload(seqno);
selinux_xfrm_notify_policyload();
}
return rc;
diff --git a/security/selinux/ss/status.c b/security/selinux/ss/status.c
new file mode 100644
index 00000000000..5d9b225f856
--- /dev/null
+++ b/security/selinux/ss/status.c
@@ -0,0 +1,129 @@
+/*
+ * mmap based event notifications for SELinux
+ *
+ * Author: KaiGai Kohei <kaigai@ak.jp.nec.com>
+ *
+ * Copyright (C) 2010 NEC corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include "avc.h"
+#include "services.h"
+
+/*
+ * The selinux_status_page shall be exposed to userspace applications
+ * using mmap interface on /selinux/status.
+ * It enables to notify applications a few events that will cause reset
+ * of userspace access vector without context switching.
+ *
+ * The selinux_kernel_status structure on the head of status page is
+ * protected from concurrent accesses using seqlock logic, so userspace
+ * application should reference the status page according to the seqlock
+ * logic.
+ *
+ * Typically, application checks status->sequence at the head of access
+ * control routine. If it is odd-number, kernel is updating the status,
+ * so please wait for a moment. If it is changed from the last sequence
+ * number, it means something happen, so application will reset userspace
+ * avc, if needed.
+ * In most cases, application shall confirm the kernel status is not
+ * changed without any system call invocations.
+ */
+static struct page *selinux_status_page = NULL;
+static DEFINE_MUTEX(selinux_status_lock);
+
+/*
+ * selinux_kernel_status_page
+ *
+ * It returns a reference to selinux_status_page. If the status page is
+ * not allocated yet, it also tries to allocate it at the first time.
+ */
+struct page *selinux_kernel_status_page(void)
+{
+ struct selinux_kernel_status *status;
+ struct page *result = NULL;
+
+ mutex_lock(&selinux_status_lock);
+ if (!selinux_status_page)
+ {
+ selinux_status_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
+ if (selinux_status_page)
+ {
+ status = page_address(selinux_status_page);
+
+ status->version = SELINUX_KERNEL_STATUS_VERSION;
+ status->sequence = 0;
+ status->enforcing = selinux_enforcing;
+ /*
+ * NOTE: the next policyload event shall set
+ * a positive value on the status->policyload,
+ * although it may not be 1, but never zero.
+ * So, application can know it was updated.
+ */
+ status->policyload = 0;
+ status->deny_unknown = !security_get_allow_unknown();
+ }
+ }
+ result = selinux_status_page;
+ mutex_unlock(&selinux_status_lock);
+
+ return result;
+}
+
+/*
+ * selinux_status_update_setenforce
+ *
+ * It updates status of the current enforcing/permissive mode.
+ */
+void selinux_status_update_setenforce(int enforcing)
+{
+ struct selinux_kernel_status *status;
+
+ mutex_lock(&selinux_status_lock);
+ if (selinux_status_page)
+ {
+ status = page_address(selinux_status_page);
+
+ status->sequence++;
+ smp_wmb();
+
+ status->enforcing = enforcing;
+
+ smp_wmb();
+ status->sequence++;
+ }
+ mutex_unlock(&selinux_status_lock);
+}
+
+/*
+ * selinux_status_update_policyload
+ *
+ * It updates status of the times of policy reloaded, and current
+ * setting of deny_unknown.
+ */
+void selinux_status_update_policyload(int seqno)
+{
+ struct selinux_kernel_status *status;
+
+ mutex_lock(&selinux_status_lock);
+ if (selinux_status_page)
+ {
+ status = page_address(selinux_status_page);
+
+ status->sequence++;
+ smp_wmb();
+
+ status->policyload = seqno;
+ status->deny_unknown = !security_get_allow_unknown();
+
+ smp_wmb();
+ status->sequence++;
+ }
+ mutex_unlock(&selinux_status_lock);
+}