Include process start time when doing polkit checks

Since PIDs can be reused, polkit prefers to be given
a (PID,start time) pair. If given a PID on its own,
it will attempt to lookup the start time in /proc/pid/stat,
though this is subject to races.

It is safer if the client app resolves the PID start
time itself, because as long as the app has the client
socket open, the client PID won't be reused.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 979e9c56a7aadf2dcfbddd1abfbad594b78b4468)

Conflicts:
	src/util/virprocess.c
	src/util/virstring.c
	src/util/virstring.h

diff --git a/daemon/remote.c b/daemon/remote.c
index 37f998f7931e54020a6ba5cbe1852af7b100ad21..175df43d2b661a12ec44abceece7f7660e1317b0 100644 (file)
--- a/daemon/remote.c
+++ b/daemon/remote.c
@@ -2372,6 +2372,7 @@ remoteDispatchAuthList(virNetServerPtr server ATTRIBUTE_UNUSED,
     uid_t callerUid;
     gid_t callerGid;
     pid_t callerPid;
+    unsigned long long timestamp;
 
     /* If the client is root then we want to bypass the
      * policykit auth to avoid root being denied if
@@ -2379,7 +2380,7 @@ remoteDispatchAuthList(virNetServerPtr server ATTRIBUTE_UNUSED,
      */
     if (auth == VIR_NET_SERVER_SERVICE_AUTH_POLKIT) {
         if (virNetServerClientGetUNIXIdentity(client, &callerUid, &callerGid,
-                                              &callerPid) < 0) {
+                                              &callerPid, &timestamp) < 0) {
             /* Don't do anything on error - it'll be validated at next
              * phase of auth anyway */
             virResetLastError();
@@ -2805,6 +2806,7 @@ remoteDispatchAuthPolkit(virNetServerPtr server ATTRIBUTE_UNUSED,
     pid_t callerPid = -1;
     gid_t callerGid = -1;
     uid_t callerUid = -1;
+    unsigned long long timestamp;
     const char *action;
     int status = -1;
     char *ident = NULL;
@@ -2830,7 +2832,7 @@ remoteDispatchAuthPolkit(virNetServerPtr server ATTRIBUTE_UNUSED,
     }
 
     if (virNetServerClientGetUNIXIdentity(client, &callerUid, &callerGid,
-                                          &callerPid) < 0) {
+                                          &callerPid, &timestamp) < 0) {
         goto authfail;
     }
 
@@ -2838,7 +2840,11 @@ remoteDispatchAuthPolkit(virNetServerPtr server ATTRIBUTE_UNUSED,
              (long long) callerPid, callerUid);
 
     virCommandAddArg(cmd, "--process");
-    virCommandAddArgFormat(cmd, "%lld", (long long) callerPid);
+    if (timestamp != 0) {
+        virCommandAddArgFormat(cmd, "%lld,%llu", (long long) callerPid, timestamp);
+    } else {
+        virCommandAddArgFormat(cmd, "%lld", (long long) callerPid);
+    }
     virCommandAddArg(cmd, "--allow-user-interaction");
 
     if (virAsprintf(&ident, "pid:%lld,uid:%d",

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 96eea0a424930b1e823e7b656d79d9014ef13a4e..1b509526097d9f631d99f68370a97e5a5a5fb870 100644 (file)
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1724,6 +1724,7 @@ virStorageFileResize;
 # util/virstring.h
 virStringFreeList;
 virStringJoin;
+virStringListLength;
 virStringSplit;
 
 

diff --git a/src/locking/lock_daemon.c b/src/locking/lock_daemon.c
index 97e5d749c2b1c0a9198c2a1d05803a46558c8dcd..bf0ee8124e705bf5d551ef46e29b77e0a3013505 100644 (file)
--- a/src/locking/lock_daemon.c
+++ b/src/locking/lock_daemon.c
@@ -782,6 +782,7 @@ virLockDaemonClientNew(virNetServerClientPtr client,
     virLockDaemonClientPtr priv;
     uid_t clientuid;
     gid_t clientgid;
+    unsigned long long timestamp;
     bool privileged = opaque != NULL;
 
     if (VIR_ALLOC(priv) < 0) {
@@ -798,7 +799,8 @@ virLockDaemonClientNew(virNetServerClientPtr client,
     if (virNetServerClientGetUNIXIdentity(client,
                                           &clientuid,
                                           &clientgid,
-                                          &priv->clientPid) < 0)
+                                          &priv->clientPid,
+                                          &timestamp) < 0)
         goto error;
 
     VIR_DEBUG("New client pid %llu uid %llu",

diff --git a/src/rpc/virnetserverclient.c b/src/rpc/virnetserverclient.c
index 58fb0b4918f58c45d1b69afb13a0f5400fcc9706..b63ae300b6bb6b7cc0c897efc341a75d7e30e322 100644 (file)
--- a/src/rpc/virnetserverclient.c
+++ b/src/rpc/virnetserverclient.c
@@ -634,12 +634,15 @@ bool virNetServerClientIsLocal(virNetServerClientPtr client)
 
 
 int virNetServerClientGetUNIXIdentity(virNetServerClientPtr client,
-                                      uid_t *uid, gid_t *gid, pid_t *pid)
+                                      uid_t *uid, gid_t *gid, pid_t *pid,
+                                      unsigned long long *timestamp)
 {
     int ret = -1;
     virObjectLock(client);
     if (client->sock)
-        ret = virNetSocketGetUNIXIdentity(client->sock, uid, gid, pid);
+        ret = virNetSocketGetUNIXIdentity(client->sock,
+                                          uid, gid, pid,
+                                          timestamp);
     virObjectUnlock(client);
     return ret;
 }
@@ -649,6 +652,7 @@ static virIdentityPtr
 virNetServerClientCreateIdentity(virNetServerClientPtr client)
 {
     char *processid = NULL;
+    char *processtime = NULL;
     char *username = NULL;
     char *groupname = NULL;
 #if WITH_SASL
@@ -662,15 +666,23 @@ virNetServerClientCreateIdentity(virNetServerClientPtr client)
         gid_t gid;
         uid_t uid;
         pid_t pid;
-        if (virNetSocketGetUNIXIdentity(client->sock, &uid, &gid, &pid) < 0)
+        unsigned long long timestamp;
+        if (virNetSocketGetUNIXIdentity(client->sock,
+                                        &uid, &gid, &pid,
+                                        &timestamp) < 0)
             goto cleanup;
 
         if (!(username = virGetUserName(uid)))
             goto cleanup;
         if (!(groupname = virGetGroupName(gid)))
             goto cleanup;
-        if (virAsprintf(&processid, "%lld",
-                        (long long)pid) < 0) {
+        if (virAsprintf(&processid, "%llu",
+                        (unsigned long long)pid) < 0) {
+            virReportOOMError();
+            goto cleanup;
+        }
+        if (virAsprintf(&processtime, "%llu",
+                        timestamp) < 0) {
             virReportOOMError();
             goto cleanup;
         }
@@ -720,6 +732,11 @@ virNetServerClientCreateIdentity(virNetServerClientPtr client)
                            VIR_IDENTITY_ATTR_UNIX_PROCESS_ID,
                            processid) < 0)
         goto error;
+    if (processtime &&
+        virIdentitySetAttr(ret,
+                           VIR_IDENTITY_ATTR_UNIX_PROCESS_TIME,
+                           processtime) < 0)
+        goto error;
 #if HAVE_SASL
     if (saslname &&
         virIdentitySetAttr(ret,
@@ -742,6 +759,7 @@ cleanup:
     VIR_FREE(username);
     VIR_FREE(groupname);
     VIR_FREE(processid);
+    VIR_FREE(processtime);
     VIR_FREE(seccontext);
 #if HAVE_SASL
     VIR_FREE(saslname);

diff --git a/src/rpc/virnetserverclient.h b/src/rpc/virnetserverclient.h
index b3b8df0bf963b7febd277649b35820c9417b4e74..2a64d45ef8b74b64d44b0905f264b73e707a9918 100644 (file)
--- a/src/rpc/virnetserverclient.h
+++ b/src/rpc/virnetserverclient.h
@@ -99,7 +99,8 @@ bool virNetServerClientIsSecure(virNetServerClientPtr client);
 bool virNetServerClientIsLocal(virNetServerClientPtr client);
 
 int virNetServerClientGetUNIXIdentity(virNetServerClientPtr client,
-                                      uid_t *uid, gid_t *gid, pid_t *pid);
+                                      uid_t *uid, gid_t *gid, pid_t *pid,
+                                      unsigned long long *timestamp);
 
 int virNetServerClientGetSecurityContext(virNetServerClientPtr client,
                                          char **context);

diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c
index c4fd9ee98157369cd8819d8e3252c8664bdb81b1..08d236ca37c7782407e6c1dcd10c1634ae27cc35 100644 (file)
--- a/src/rpc/virnetsocket.c
+++ b/src/rpc/virnetsocket.c
@@ -1103,31 +1103,41 @@ int virNetSocketGetPort(virNetSocketPtr sock)
 int virNetSocketGetUNIXIdentity(virNetSocketPtr sock,
                                 uid_t *uid,
                                 gid_t *gid,
-                                pid_t *pid)
+                                pid_t *pid,
+                                unsigned long long *timestamp)
 {
     struct ucred cr;
     socklen_t cr_len = sizeof(cr);
+    int ret = -1;
+
     virObjectLock(sock);
 
     if (getsockopt(sock->fd, SOL_SOCKET, SO_PEERCRED, &cr, &cr_len) < 0) {
         virReportSystemError(errno, "%s",
                              _("Failed to get client socket identity"));
-        virObjectUnlock(sock);
-        return -1;
+        goto cleanup;
     }
 
+    if (virProcessGetStartTime(cr.pid, timestamp) < 0)
+        goto cleanup;
+
     *pid = cr.pid;
     *uid = cr.uid;
     *gid = cr.gid;
 
+    ret = 0;
+
+cleanup:
     virObjectUnlock(sock);
-    return 0;
+    return ret;
 }
 #elif defined(LOCAL_PEERCRED)
+
 int virNetSocketGetUNIXIdentity(virNetSocketPtr sock,
                                 uid_t *uid,
                                 gid_t *gid,
-                                pid_t *pid)
+                                pid_t *pid,
+                                unsigned long long *timestamp ATTRIBUTE_UNUSED)
 {
     struct xucred cr;
     socklen_t cr_len = sizeof(cr);
@@ -1151,7 +1161,8 @@ int virNetSocketGetUNIXIdentity(virNetSocketPtr sock,
 int virNetSocketGetUNIXIdentity(virNetSocketPtr sock ATTRIBUTE_UNUSED,
                                 uid_t *uid ATTRIBUTE_UNUSED,
                                 gid_t *gid ATTRIBUTE_UNUSED,
-                                pid_t *pid ATTRIBUTE_UNUSED)
+                                pid_t *pid ATTRIBUTE_UNUSED,
+                                unsigned long long *timestamp ATTRIBUTE_UNUSED)
 {
     /* XXX Many more OS support UNIX socket credentials we could port to. See dbus ....*/
     virReportSystemError(ENOSYS, "%s",

diff --git a/src/rpc/virnetsocket.h b/src/rpc/virnetsocket.h
index 7392c722bf33e9336d81e2acca7988fc9b2290fc..a0536f262ddaee7a31e4778e146e49d8c23b1c60 100644 (file)
--- a/src/rpc/virnetsocket.h
+++ b/src/rpc/virnetsocket.h
@@ -113,7 +113,8 @@ int virNetSocketGetPort(virNetSocketPtr sock);
 int virNetSocketGetUNIXIdentity(virNetSocketPtr sock,
                                 uid_t *uid,
                                 gid_t *gid,
-                                pid_t *pid);
+                                pid_t *pid,
+                                unsigned long long *timestamp);
 int virNetSocketGetSecurityContext(virNetSocketPtr sock,
                                    char **context);
 

diff --git a/src/util/viridentity.h b/src/util/viridentity.h
index 39ab20ef9ee62eadd0a6f993c00671cc77052255..78680b51d3de58a4f1ffb3a7dc26c879a14d3f79 100644 (file)
--- a/src/util/viridentity.h
+++ b/src/util/viridentity.h
@@ -31,6 +31,7 @@ typedef enum {
       VIR_IDENTITY_ATTR_UNIX_USER_NAME,
       VIR_IDENTITY_ATTR_UNIX_GROUP_NAME,
       VIR_IDENTITY_ATTR_UNIX_PROCESS_ID,
+      VIR_IDENTITY_ATTR_UNIX_PROCESS_TIME,
       VIR_IDENTITY_ATTR_SASL_USER_NAME,
       VIR_IDENTITY_ATTR_X509_DISTINGUISHED_NAME,
       VIR_IDENTITY_ATTR_SECURITY_CONTEXT,

diff --git a/src/util/virprocess.c b/src/util/virprocess.c
index a492bd11f77103b3bb5f37773010faf1fadadfb6..4202d9c5d7c69feeec3f7679eb49d4a8c921e7b6 100644 (file)
--- a/src/util/virprocess.c
+++ b/src/util/virprocess.c
@@ -29,12 +29,20 @@
 #include <sys/wait.h>
 #include <sched.h>
 
+#ifdef __FreeBSD__
+# include <sys/param.h>
+# include <sys/sysctl.h>
+# include <sys/user.h>
+#endif
+
+#include "viratomic.h"
 #include "virprocess.h"
 #include "virerror.h"
 #include "viralloc.h"
 #include "virfile.h"
 #include "virlog.h"
 #include "virutil.h"
+#include "virstring.h"
 
 #define VIR_FROM_THIS VIR_FROM_NONE
 
@@ -605,3 +613,112 @@ int virProcessSetNamespaces(size_t nfdlist ATTRIBUTE_UNUSED,
     return -1;
 }
 #endif /* ! HAVE_SETNS */
+
+#ifdef __linux__
+/*
+ * Port of code from polkitunixprocess.c under terms
+ * of the LGPLv2+
+ */
+int virProcessGetStartTime(pid_t pid,
+                           unsigned long long *timestamp)
+{
+    char *filename = NULL;
+    char *buf = NULL;
+    char *tmp;
+    int ret = -1;
+    int len;
+    char **tokens = NULL;
+
+    if (virAsprintf(&filename, "/proc/%llu/stat",
+                    (unsigned long long)pid) < 0) {
+        virReportOOMError();
+        return -1;
+    }
+
+    if ((len = virFileReadAll(filename, 1024, &buf)) < 0)
+        goto cleanup;
+
+    /* start time is the token at index 19 after the '(process name)' entry - since only this
+     * field can contain the ')' character, search backwards for this to avoid malicious
+     * processes trying to fool us
+     */
+
+    if (!(tmp = strrchr(buf, ')'))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Cannot find start time in %s"),
+                       filename);
+        goto cleanup;
+    }
+    tmp += 2; /* skip ') ' */
+    if ((tmp - buf) >= len) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Cannot find start time in %s"),
+                       filename);
+        goto cleanup;
+    }
+
+    tokens = virStringSplit(tmp, " ", 0);
+
+    if (virStringListLength(tokens) < 20) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Cannot find start time in %s"),
+                       filename);
+        goto cleanup;
+    }
+
+    if (virStrToLong_ull(tokens[19],
+                         NULL,
+                         10,
+                         timestamp) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("Cannot parse start time %s in %s"),
+                       tokens[19], filename);
+        goto cleanup;
+    }
+
+    ret = 0;
+
+cleanup:
+    virStringFreeList(tokens);
+    VIR_FREE(filename);
+    VIR_FREE(buf);
+    return ret;
+}
+#elif defined(__FreeBSD__)
+int virProcessGetStartTime(pid_t pid,
+                           unsigned long long *timestamp)
+{
+    struct kinfo_proc p;
+    int mib[4];
+    size_t len = 4;
+
+    sysctlnametomib("kern.proc.pid", mib, &len);
+
+    len = sizeof(struct kinfo_proc);
+    mib[3] = pid;
+
+    if (sysctl(mib, 4, &p, &len, NULL, 0) < 0) {
+        virReportSystemError(errno, "%s",
+                             _("Unable to query process ID start time"));
+        return -1;
+    }
+
+    *timestamp = (unsigned long long)p.ki_start.tv_sec;
+
+    return 0;
+
+}
+#else
+int virProcessGetStartTime(pid_t pid,
+                           unsigned long long *timestamp)
+{
+    static int warned = 0;
+    if (virAtomicIntInc(&warned) == 1) {
+        VIR_WARN("Process start time of pid %llu not available on this platform",
+                 (unsigned long long)pid);
+        warned = true;
+    }
+    *timestamp = 0;
+    return 0;
+}
+#endif

diff --git a/src/util/virprocess.h b/src/util/virprocess.h
index 53475d3cc3ff3410d6c13f6c9cfe0dd427616ba0..149d451a61f010dc6b1b7dd3e47e35790320dc86 100644 (file)
--- a/src/util/virprocess.h
+++ b/src/util/virprocess.h
@@ -47,6 +47,9 @@ int virProcessGetAffinity(pid_t pid,
                           virBitmapPtr *map,
                           int maxcpu);
 
+int virProcessGetStartTime(pid_t pid,
+                           unsigned long long *timestamp);
+
 int virProcessGetNamespaces(pid_t pid,
                             size_t *nfdlist,
                             int **fdlist);

diff --git a/src/util/virstring.c b/src/util/virstring.c
index 0420ca37f9d2fcc5829a06a2fa1ec270f73deee6..1fc24de9a184c9f8933ff673f550fbe61d17f23e 100644 (file)
--- a/src/util/virstring.c
+++ b/src/util/virstring.c
@@ -166,3 +166,13 @@ void virStringFreeList(char **strings)
     }
     VIR_FREE(strings);
 }
+
+size_t virStringListLength(char **strings)
+{
+    size_t i = 0;
+
+    while (strings && strings[i])
+        i++;
+
+    return i;
+}

diff --git a/src/util/virstring.h b/src/util/virstring.h
index a569fe080a6262e5af1b49452646a8b2b2a72f3b..8d1995a48b88586deeb3b3e8c029a22544784b84 100644 (file)
--- a/src/util/virstring.h
+++ b/src/util/virstring.h
@@ -35,4 +35,8 @@ char *virStringJoin(const char **strings,
 
 void virStringFreeList(char **strings);
 
+bool virStringArrayHasString(char **strings, const char *needle);
+
+size_t virStringListLength(char **strings);
+
 #endif /* __VIR_STRING_H__ */