linux-kernel - [PATCH 3/9] Add a mode on the struct probe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 05 Mar 2008 20:32:44 +0300
From:	Pavel Emelyanov <xemul@...nvz.org>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Paul Menage <menage@...gle.com>,
	Sukadev Bhattiprolu <sukadev@...ibm.com>,
	Serge Hallyn <serue@...ibm.com>
Subject: [PATCH 3/9] Add a mode on the struct probe

The idea of the set is to make the dev_t to struct kobj map
be per-cgroup, and provide a permissions for this mapping.
This mode mask will operate with FMODE_xxx modes.

To achieve this, I add the mode_t mode on the struct probe,
which sets this mapping, and move the locked part of the 
kobj_map() into a separate function, which also accepts the 
mode to be set on the probe.

By default all the modes are provided for a map.

Signed-off-by: Pavel Emelyanov <xemul@...nvz.org>

---
 drivers/base/map.c |   31 ++++++++++++++++++++++++++-----
 1 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/drivers/base/map.c b/drivers/base/map.c
index 7de565f..c7e28a1 100644
--- a/drivers/base/map.c
+++ b/drivers/base/map.c
@@ -15,6 +15,7 @@
 #include <linux/kdev_t.h>
 #include <linux/kobject.h>
 #include <linux/kobj_map.h>
+#include <linux/fs.h>
 
 #define KOBJ_MAP_PROBES	255
 
@@ -22,6 +23,7 @@ struct kobj_map {
 	struct probe {
 		struct probe *next;
 		dev_t dev;
+		mode_t mode;
 		unsigned long range;
 		struct module *owner;
 		kobj_probe_t *get;
@@ -31,9 +33,9 @@ struct kobj_map {
 	struct mutex *lock;
 };
 
-int kobj_map(struct kobj_map *domain, dev_t dev, unsigned long range,
-	     struct module *module, kobj_probe_t *probe,
-	     int (*lock)(dev_t, void *), void *data)
+static int __kobj_map(struct kobj_map *domain, dev_t dev, mode_t mode,
+		unsigned long range, struct module *module,
+		kobj_probe_t *probe, int (*lock)(dev_t, void *), void *data)
 {
 	unsigned n = MAJOR(dev + range - 1) - MAJOR(dev) + 1;
 	unsigned index = MAJOR(dev);
@@ -55,8 +57,15 @@ int kobj_map(struct kobj_map *domain, dev_t dev, unsigned long range,
 		p->dev = dev;
 		p->range = range;
 		p->data = data;
+		/*
+		 * When opening a device we want to (dis)allow only
+		 * read or write. But sys_open() can provide more
+		 * modes like lseek or pread. So, these FMODE-s are
+		 * always 'on'.
+		 */
+		p->mode = mode | FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
 	}
-	mutex_lock(domain->lock);
+
 	for (i = 0, p -= n; i < n; i++, p++, index++) {
 		struct probe **s = &domain->probes[index % KOBJ_MAP_PROBES];
 		while (*s && (*s)->range < range)
@@ -64,10 +73,22 @@ int kobj_map(struct kobj_map *domain, dev_t dev, unsigned long range,
 		p->next = *s;
 		*s = p;
 	}
-	mutex_unlock(domain->lock);
 	return 0;
 }
 
+int kobj_map(struct kobj_map *domain, dev_t dev, unsigned long range,
+	     struct module *module, kobj_probe_t *probe,
+	     int (*lock)(dev_t, void *), void *data)
+{
+	int err;
+
+	mutex_lock(domain->lock);
+	err = __kobj_map(domain, dev, FMODE_READ | FMODE_WRITE, range,
+			module, probe, lock, data);
+	mutex_unlock(domain->lock);
+	return err;
+}
+
 void kobj_unmap(struct kobj_map *domain, dev_t dev, unsigned long range)
 {
 	unsigned n = MAJOR(dev + range - 1) - MAJOR(dev) + 1;
-- 
1.5.3.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/