Re: [PATCH v3 3/3] selinux: add permission names to trace event

From: Steven Rostedt
Date: Tue Aug 18 2020 - 12:09:59 EST


On Mon, 17 Aug 2020 16:29:33 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Mon, 17 Aug 2020 16:13:29 -0400
> Stephen Smalley <stephen.smalley.work@xxxxxxxxx> wrote:
>
> > Does this require a corresponding patch to userspace?  Otherwise, I get
> > the following:
> >
> > libtraceevent: No such file or directory
> >   [avc:selinux_audited] function avc_trace_perm_to_name not defined
>
> Yes, we need to add a plugin to libtraceevent that will add that
> function.
>
> I could possibly write one up real quick.

Something like this (this is patched on top of trace-cmd, but will work
for tools/lib/traceevent too).

With CONFIG_TRACE_EVENT_INJECT enabled (to test events), I did the following:

# echo 'utclass=1 audited=1 denied=0' > /sys/kernel/tracing/events/avc/selinux_audited/inject
# trace-cmd extract
# trace-cmd report
cpus=8
<...>-1685 [005] 1607.612032: selinux_audited: requested=0x0 denied=0x0 audited=0x1 result=0 scontext= tcontext= tclass= permissions={ compute_av }

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

---
diff --git a/lib/traceevent/plugins/Makefile b/lib/traceevent/plugins/Makefile
index 21e933af..13cbcb92 100644
--- a/lib/traceevent/plugins/Makefile
+++ b/lib/traceevent/plugins/Makefile
@@ -16,6 +16,7 @@ PLUGIN_OBJS += plugin_scsi.o
PLUGIN_OBJS += plugin_cfg80211.o
PLUGIN_OBJS += plugin_blk.o
PLUGIN_OBJS += plugin_tlb.o
+PLUGIN_OBJS += plugin_avc.o

PLUGIN_OBJS := $(PLUGIN_OBJS:%.o=$(bdir)/%.o)
PLUGIN_BUILD := $(PLUGIN_OBJS:$(bdir)/%.o=$(bdir)/%.so)
diff --git a/lib/traceevent/plugins/plugin_avc.c b/lib/traceevent/plugins/plugin_avc.c
new file mode 100644
index 00000000..76af23b9
--- /dev/null
+++ b/lib/traceevent/plugins/plugin_avc.c
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <string.h>
+#include "event-parse.h"
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+typedef unsigned short u16;
+
+/* Class/perm mapping support */
+struct security_class_mapping {
+ const char *name;
+ const char *perms[sizeof(unsigned) * 8 + 1];
+};
+
+#define COMMON_FILE_SOCK_PERMS "ioctl", "read", "write", "create", \
+ "getattr", "setattr", "lock", "relabelfrom", "relabelto", "append", "map"
+
+#define COMMON_FILE_PERMS COMMON_FILE_SOCK_PERMS, "unlink", "link", \
+ "rename", "execute", "quotaon", "mounton", "audit_access", \
+ "open", "execmod", "watch", "watch_mount", "watch_sb", \
+ "watch_with_perm", "watch_reads"
+
+#define COMMON_SOCK_PERMS COMMON_FILE_SOCK_PERMS, "bind", "connect", \
+ "listen", "accept", "getopt", "setopt", "shutdown", "recvfrom", \
+ "sendto", "name_bind"
+
+#define COMMON_IPC_PERMS "create", "destroy", "getattr", "setattr", "read", \
+ "write", "associate", "unix_read", "unix_write"
+
+#define COMMON_CAP_PERMS "chown", "dac_override", "dac_read_search", \
+ "fowner", "fsetid", "kill", "setgid", "setuid", "setpcap", \
+ "linux_immutable", "net_bind_service", "net_broadcast", \
+ "net_admin", "net_raw", "ipc_lock", "ipc_owner", "sys_module", \
+ "sys_rawio", "sys_chroot", "sys_ptrace", "sys_pacct", "sys_admin", \
+ "sys_boot", "sys_nice", "sys_resource", "sys_time", \
+ "sys_tty_config", "mknod", "lease", "audit_write", \
+ "audit_control", "setfcap"
+
+#define COMMON_CAP2_PERMS "mac_override", "mac_admin", "syslog", \
+ "wake_alarm", "block_suspend", "audit_read", "perfmon", "bpf"
+
+/*
+ * Note: The name for any socket class should be suffixed by "socket",
+ * and doesn't contain more than one substr of "socket".
+ */
+struct security_class_mapping secclass_map[] = {
+ { "security",
+ { "compute_av", "compute_create", "compute_member",
+ "check_context", "load_policy", "compute_relabel",
+ "compute_user", "setenforce", "setbool", "setsecparam",
+ "setcheckreqprot", "read_policy", "validate_trans", NULL } },
+ { "process",
+ { "fork", "transition", "sigchld", "sigkill",
+ "sigstop", "signull", "signal", "ptrace", "getsched", "setsched",
+ "getsession", "getpgid", "setpgid", "getcap", "setcap", "share",
+ "getattr", "setexec", "setfscreate", "noatsecure", "siginh",
+ "setrlimit", "rlimitinh", "dyntransition", "setcurrent",
+ "execmem", "execstack", "execheap", "setkeycreate",
+ "setsockcreate", "getrlimit", NULL } },
+ { "process2",
+ { "nnp_transition", "nosuid_transition", NULL } },
+ { "system",
+ { "ipc_info", "syslog_read", "syslog_mod",
+ "syslog_console", "module_request", "module_load", NULL } },
+ { "capability",
+ { COMMON_CAP_PERMS, NULL } },
+ { "filesystem",
+ { "mount", "remount", "unmount", "getattr",
+ "relabelfrom", "relabelto", "associate", "quotamod",
+ "quotaget", "watch", NULL } },
+ { "file",
+ { COMMON_FILE_PERMS,
+ "execute_no_trans", "entrypoint", NULL } },
+ { "dir",
+ { COMMON_FILE_PERMS, "add_name", "remove_name",
+ "reparent", "search", "rmdir", NULL } },
+ { "fd", { "use", NULL } },
+ { "lnk_file",
+ { COMMON_FILE_PERMS, NULL } },
+ { "chr_file",
+ { COMMON_FILE_PERMS, NULL } },
+ { "blk_file",
+ { COMMON_FILE_PERMS, NULL } },
+ { "sock_file",
+ { COMMON_FILE_PERMS, NULL } },
+ { "fifo_file",
+ { COMMON_FILE_PERMS, NULL } },
+ { "socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "tcp_socket",
+ { COMMON_SOCK_PERMS,
+ "node_bind", "name_connect",
+ NULL } },
+ { "udp_socket",
+ { COMMON_SOCK_PERMS,
+ "node_bind", NULL } },
+ { "rawip_socket",
+ { COMMON_SOCK_PERMS,
+ "node_bind", NULL } },
+ { "node",
+ { "recvfrom", "sendto", NULL } },
+ { "netif",
+ { "ingress", "egress", NULL } },
+ { "netlink_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "packet_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "key_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "unix_stream_socket",
+ { COMMON_SOCK_PERMS, "connectto", NULL } },
+ { "unix_dgram_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "sem",
+ { COMMON_IPC_PERMS, NULL } },
+ { "msg", { "send", "receive", NULL } },
+ { "msgq",
+ { COMMON_IPC_PERMS, "enqueue", NULL } },
+ { "shm",
+ { COMMON_IPC_PERMS, "lock", NULL } },
+ { "ipc",
+ { COMMON_IPC_PERMS, NULL } },
+ { "netlink_route_socket",
+ { COMMON_SOCK_PERMS,
+ "nlmsg_read", "nlmsg_write", NULL } },
+ { "netlink_tcpdiag_socket",
+ { COMMON_SOCK_PERMS,
+ "nlmsg_read", "nlmsg_write", NULL } },
+ { "netlink_nflog_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_xfrm_socket",
+ { COMMON_SOCK_PERMS,
+ "nlmsg_read", "nlmsg_write", NULL } },
+ { "netlink_selinux_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_iscsi_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_audit_socket",
+ { COMMON_SOCK_PERMS,
+ "nlmsg_read", "nlmsg_write", "nlmsg_relay", "nlmsg_readpriv",
+ "nlmsg_tty_audit", NULL } },
+ { "netlink_fib_lookup_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_connector_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_netfilter_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_dnrt_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "association",
+ { "sendto", "recvfrom", "setcontext", "polmatch", NULL } },
+ { "netlink_kobject_uevent_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_generic_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_scsitransport_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_rdma_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netlink_crypto_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "appletalk_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "packet",
+ { "send", "recv", "relabelto", "forward_in", "forward_out", NULL } },
+ { "key",
+ { "view", "read", "write", "search", "link", "setattr", "create",
+ NULL } },
+ { "dccp_socket",
+ { COMMON_SOCK_PERMS,
+ "node_bind", "name_connect", NULL } },
+ { "memprotect", { "mmap_zero", NULL } },
+ { "peer", { "recv", NULL } },
+ { "capability2",
+ { COMMON_CAP2_PERMS, NULL } },
+ { "kernel_service", { "use_as_override", "create_files_as", NULL } },
+ { "tun_socket",
+ { COMMON_SOCK_PERMS, "attach_queue", NULL } },
+ { "binder", { "impersonate", "call", "set_context_mgr", "transfer",
+ NULL } },
+ { "cap_userns",
+ { COMMON_CAP_PERMS, NULL } },
+ { "cap2_userns",
+ { COMMON_CAP2_PERMS, NULL } },
+ { "sctp_socket",
+ { COMMON_SOCK_PERMS,
+ "node_bind", "name_connect", "association", NULL } },
+ { "icmp_socket",
+ { COMMON_SOCK_PERMS,
+ "node_bind", NULL } },
+ { "ax25_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "ipx_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "netrom_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "atmpvc_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "x25_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "rose_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "decnet_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "atmsvc_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "rds_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "irda_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "pppox_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "llc_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "can_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "tipc_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "bluetooth_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "iucv_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "rxrpc_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "isdn_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "phonet_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "ieee802154_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "caif_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "alg_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "nfc_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "vsock_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "kcm_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "qipcrtr_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "smc_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "infiniband_pkey",
+ { "access", NULL } },
+ { "infiniband_endport",
+ { "manage_subnet", NULL } },
+ { "bpf",
+ {"map_create", "map_read", "map_write", "prog_load", "prog_run"} },
+ { "xdp_socket",
+ { COMMON_SOCK_PERMS, NULL } },
+ { "perf_event",
+ {"open", "cpu", "kernel", "tracepoint", "read", "write"} },
+ { "lockdown",
+ { "integrity", "confidentiality", NULL } },
+ { NULL }
+ };
+
+
+static unsigned long long
+avc_trace_perm_to_name(struct trace_seq *p, unsigned long long *args)
+{
+ u16 tclass = args[1];
+ int av = args[2];
+ int avdenied = args[3];
+ int i, perm;
+ const char **perms;
+
+ if (!tclass || tclass >= ARRAY_SIZE(secclass_map))
+ return 0;
+
+ perms = secclass_map[tclass-1].perms;
+
+ i = 0;
+ perm = 1;
+ while (i < (sizeof(av) * 8)) {
+ if ((perm & av) && perms[i]) {
+ if (!(perm & avdenied))
+ trace_seq_printf(p, " %s", perms[i]);
+ else
+ trace_seq_printf(p, " !%s", perms[i]);
+ av &= ~perm;
+ }
+ i++;
+ perm <<= 1;
+ }
+
+ return 0;
+}
+
+int TEP_PLUGIN_LOADER(struct tep_handle *tep)
+{
+ tep_register_print_function(tep,
+ avc_trace_perm_to_name,
+ TEP_FUNC_ARG_STRING,
+ "avc_trace_perm_to_name",
+ TEP_FUNC_ARG_PTR,
+ TEP_FUNC_ARG_INT,
+ TEP_FUNC_ARG_INT,
+ TEP_FUNC_ARG_INT,
+ TEP_FUNC_ARG_VOID);
+
+ return 0;
+}
+
+void TEP_PLUGIN_UNLOADER(struct tep_handle *tep)
+{
+ tep_unregister_print_function(tep, avc_trace_perm_to_name,
+ "avc_trace_perm_to_name");
+}