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authorJeff Mahoney <jeffm@suse.com>2013-07-03 10:18:30 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2013-07-15 12:48:22 +1000
commite9f4d4fbcd492d0fe9b2e4f3f4c945b947ac3905 (patch)
tree36a8a97e261d1f670f85bcead174a55514323644 /drivers/isdn
parentbdeaefef8a1ec9035e76dcadff76944cdbeb2975 (diff)
mISDN: add support for group membership check
This patch adds a module parameter to allow a group access to the mISDN devices. Otherwise, unpriviledged users on systems with ISDN hardware have the ability to dial out, potentially causing expensive bills. Based on a different implementation by Patrick Koppen. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Jeff Mahoney <jeffm@suse.com> Cc: Patrick Koppen <isdn4linux@koppen.de> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/isdn')
-rw-r--r--drivers/isdn/mISDN/core.c6
-rw-r--r--drivers/isdn/mISDN/core.h1
-rw-r--r--drivers/isdn/mISDN/socket.c9
3 files changed, 16 insertions, 0 deletions
diff --git a/drivers/isdn/mISDN/core.c b/drivers/isdn/mISDN/core.c
index da30c5cb9609..174aa3f17afb 100644
--- a/drivers/isdn/mISDN/core.c
+++ b/drivers/isdn/mISDN/core.c
@@ -21,10 +21,14 @@
#include "core.h"
static u_int debug;
+static u_int gid;
+kgid_t misdn_permitted_gid;
MODULE_AUTHOR("Karsten Keil");
MODULE_LICENSE("GPL");
module_param(debug, uint, S_IRUGO | S_IWUSR);
+module_param(gid, uint, 0);
+MODULE_PARM_DESC(gid, "Unix group for accessing misdn socket (default 0)");
static u64 device_ids;
#define MAX_DEVICE_ID 63
@@ -372,6 +376,8 @@ mISDNInit(void)
{
int err;
+ misdn_permitted_gid = make_kgid(current_user_ns(), gid);
+
printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n",
MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE);
mISDN_init_clock(&debug);
diff --git a/drivers/isdn/mISDN/core.h b/drivers/isdn/mISDN/core.h
index 52695bb81ee7..5f509bf93c00 100644
--- a/drivers/isdn/mISDN/core.h
+++ b/drivers/isdn/mISDN/core.h
@@ -17,6 +17,7 @@
extern struct mISDNdevice *get_mdevice(u_int);
extern int get_mdevice_count(void);
+extern kgid_t misdn_permitted_gid;
/* stack status flag */
#define mISDN_STACK_ACTION_MASK 0x0000ffff
diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index e47dcb9d1e91..8dcef368e9da 100644
--- a/drivers/isdn/mISDN/socket.c
+++ b/drivers/isdn/mISDN/socket.c
@@ -612,6 +612,11 @@ data_sock_create(struct net *net, struct socket *sock, int protocol)
{
struct sock *sk;
+ if (!capable(CAP_SYS_ADMIN) &&
+ !gid_eq(misdn_permitted_gid, current_gid()) &&
+ !in_group_p(misdn_permitted_gid))
+ return -EPERM;
+
if (sock->type != SOCK_DGRAM)
return -ESOCKTNOSUPPORT;
@@ -694,6 +699,10 @@ base_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
case IMSETDEVNAME:
{
struct mISDN_devrename dn;
+ if (!capable(CAP_SYS_ADMIN) &&
+ !gid_eq(misdn_permitted_gid, current_gid()) &&
+ !in_group_p(misdn_permitted_gid))
+ return -EPERM;
if (copy_from_user(&dn, (void __user *)arg,
sizeof(dn))) {
err = -EFAULT;