From: Jeff Mahoney <[email protected]> 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 <[email protected]>. [v2] - convert to the new UID/GID API - fix whitespace issues (per Sergei) Acked-by: Jeff Mahoney <[email protected]> Cc: Patrick Koppen <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> Cc: Karsten Keil <[email protected]> Cc: [email protected] Cc: "David S. Miller" <[email protected]> Cc: Sergei Shtylyov <[email protected]> --- drivers/isdn/mISDN/core.c | 6 ++++++ drivers/isdn/mISDN/core.h | 1 + drivers/isdn/mISDN/socket.c | 9 +++++++++ 3 files changed, 16 insertions(+) diff --git a/drivers/isdn/mISDN/core.c b/drivers/isdn/mISDN/core.c index da30c5c..174aa3f 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 52695bb..5f509bf 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 e47dcb9..8dcef36 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; -- 1.8.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
