lockd: Add helper to sanity check incoming NOTIFY requests

lockd accepts SM_NOTIFY calls only from a privileged process on the
local system.  If lockd uses an AF_INET6 listener, the sender's address
(ie the local rpc.statd) will be the IPv6 loopback address, not the
IPv4 loopback address.

Make sure the privilege test in nlmsvc_proc_sm_notify() and
nlm4svc_proc_sm_notify() works for both AF_INET and AF_INET6 family
addresses by refactoring the test into a helper and adding support for
IPv6 addresses.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index 50ee8eb139ab9deee8fcb60185f9f957417c4d6c..014f6ce48172fa73cc5d534bda12096776b39e20 100644 (file)
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -421,11 +421,9 @@ nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 {
        struct sockaddr_in      saddr;
 
-       memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
-
        dprintk("lockd: SM_NOTIFY     called\n");
-       if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
-        || ntohs(saddr.sin_port) >= 1024) {
+
+       if (!nlm_privileged_requester(rqstp)) {
                char buf[RPC_MAX_ADDRBUFLEN];
                printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
                                svc_print_addr(rqstp, buf, sizeof(buf)));

diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index 935ce967a6a1407e62024fcba62912950eb16373..548b0bb2b84d1e7dccb6351bdff03980d276959e 100644 (file)
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -453,11 +453,9 @@ nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
 {
        struct sockaddr_in      saddr;
 
-       memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
-
        dprintk("lockd: SM_NOTIFY     called\n");
-       if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
-        || ntohs(saddr.sin_port) >= 1024) {
+
+       if (!nlm_privileged_requester(rqstp)) {
                char buf[RPC_MAX_ADDRBUFLEN];
                printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
                                svc_print_addr(rqstp, buf, sizeof(buf)));

diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index e6b070979287fda5e44fc27621a5d875fbf97352..b56d5aa9b194c0d87296b303874d331b84246413 100644 (file)
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -277,6 +277,47 @@ static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
        return file->f_file->f_path.dentry->d_inode;
 }
 
+static inline int __nlm_privileged_request4(const struct sockaddr *sap)
+{
+       const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+       return (sin->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) &&
+                       (ntohs(sin->sin_port) < 1024);
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static inline int __nlm_privileged_request6(const struct sockaddr *sap)
+{
+       const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+       return (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK) &&
+                       (ntohs(sin6->sin6_port) < 1024);
+}
+#else  /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
+static inline int __nlm_privileged_request6(const struct sockaddr *sap)
+{
+       return 0;
+}
+#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
+
+/*
+ * Ensure incoming requests are from local privileged callers.
+ *
+ * Return TRUE if sender is local and is connecting via a privileged port;
+ * otherwise return FALSE.
+ */
+static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
+{
+       const struct sockaddr *sap = svc_addr(rqstp);
+
+       switch (sap->sa_family) {
+       case AF_INET:
+               return __nlm_privileged_request4(sap);
+       case AF_INET6:
+               return __nlm_privileged_request6(sap);
+       default:
+               return 0;
+       }
+}
+
 static inline int __nlm_cmp_addr4(const struct sockaddr *sap1,
                                  const struct sockaddr *sap2)
 {