diff options
| -rw-r--r-- | fs/lockd/mon.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index 99aec744474c..8ae4c02d7dfd 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -9,6 +9,8 @@ #include <linux/types.h> #include <linux/utsname.h> #include <linux/kernel.h> +#include <linux/ktime.h> + #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/xprtsock.h> #include <linux/sunrpc/svc.h> @@ -240,13 +242,25 @@ static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv) * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these * requests. * - * Linux provides the raw IP address of the monitored host, - * left in network byte order. + * The NSM protocol requires that these cookies be unique while the + * system is running. We prefer a stronger requirement of making them + * unique across reboots. If user space bugs cause a stale cookie to + * be sent to the kernel, it could cause the wrong host to lose its + * lock state if cookies were not unique across reboots. + * + * The cookies are exposed only to local user space via loopback. They + * do not appear on the physical network. If we want greater security + * for some reason, nsm_init_private() could perform a one-way hash to + * obscure the contents of the cookie. */ static void nsm_init_private(struct nsm_handle *nsm) { - __be32 *p = (__be32 *)&nsm->sm_priv.data; - *p = nsm_addr_in(nsm)->sin_addr.s_addr; + u64 *p = (u64 *)&nsm->sm_priv.data; + struct timespec ts; + + ktime_get_ts(&ts); + *p++ = timespec_to_ns(&ts); + *p = (unsigned long)nsm; } static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap, @@ -351,11 +365,7 @@ struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info) spin_lock(&nsm_lock); - if (nsm_use_hostnames && info->mon != NULL) - cached = nsm_lookup_hostname(info->mon, info->len); - else - cached = nsm_lookup_priv(&info->priv); - + cached = nsm_lookup_priv(&info->priv); if (unlikely(cached == NULL)) { spin_unlock(&nsm_lock); dprintk("lockd: never saw rebooted peer '%.*s' before\n", |