From 3a101b8de0d39403b2c7e5c23fd0b005668acf48 Mon Sep 17 00:00:00 2001 From: Richard Guy Briggs Date: Tue, 22 Apr 2014 21:31:56 -0400 Subject: [PATCH] audit: add netlink audit protocol bind to check capabilities on multicast join Register a netlink per-protocol bind fuction for audit to check userspace process capabilities before allowing a multicast group connection. Signed-off-by: Richard Guy Briggs Signed-off-by: David S. Miller --- include/uapi/linux/capability.h | 7 ++++++- kernel/audit.c | 10 ++++++++++ security/selinux/include/classmap.h | 2 +- 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 154dd6d3c8fe..12c37a197d24 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -347,7 +347,12 @@ struct vfs_cap_data { #define CAP_BLOCK_SUSPEND 36 -#define CAP_LAST_CAP CAP_BLOCK_SUSPEND +/* Allow reading the audit log via multicast netlink socket */ + +#define CAP_AUDIT_READ 37 + + +#define CAP_LAST_CAP CAP_AUDIT_READ #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) diff --git a/kernel/audit.c b/kernel/audit.c index 7c2893602d06..223cb746f141 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1076,10 +1076,20 @@ static void audit_receive(struct sk_buff *skb) mutex_unlock(&audit_cmd_mutex); } +/* Run custom bind function on netlink socket group connect or bind requests. */ +static int audit_bind(int group) +{ + if (!capable(CAP_AUDIT_READ)) + return -EPERM; + + return 0; +} + static int __net_init audit_net_init(struct net *net) { struct netlink_kernel_cfg cfg = { .input = audit_receive, + .bind = audit_bind, }; struct audit_net *aunet = net_generic(net, audit_net_id); diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index 14d04e63b1f0..be491a74c1ed 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -147,7 +147,7 @@ struct security_class_mapping secclass_map[] = { { "peer", { "recv", NULL } }, { "capability2", { "mac_override", "mac_admin", "syslog", "wake_alarm", "block_suspend", - NULL } }, + "audit_read", NULL } }, { "kernel_service", { "use_as_override", "create_files_as", NULL } }, { "tun_socket", { COMMON_SOCK_PERMS, "attach_queue", NULL } }, -- 2.20.1