From 0ad95472bf169a3501991f8f33f5147f792a8116 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Wed, 23 Sep 2015 15:49:29 +0300 Subject: [PATCH] lockd: create NSM handles per net namespace Commit cb7323fffa85 ("lockd: create and use per-net NSM RPC clients on MON/UNMON requests") introduced per-net NSM RPC clients. Unfortunately this doesn't make any sense without per-net nsm_handle. E.g. the following scenario could happen Two hosts (X and Y) in different namespaces (A and B) share the same nsm struct. 1. nsm_monitor(host_X) called => NSM rpc client created, nsm->sm_monitored bit set. 2. nsm_mointor(host-Y) called => nsm->sm_monitored already set, we just exit. Thus in namespace B ln->nsm_clnt == NULL. 3. host X destroyed => nsm->sm_count decremented to 1 4. host Y destroyed => nsm_unmonitor() => nsm_mon_unmon() => NULL-ptr dereference of *ln->nsm_clnt So this could be fixed by making per-net nsm_handles list, instead of global. Thus different net namespaces will not be able share the same nsm_handle. Signed-off-by: Andrey Ryabinin Cc: Signed-off-by: J. Bruce Fields --- fs/lockd/host.c | 7 ++++--- fs/lockd/mon.c | 36 ++++++++++++++++++++++-------------- fs/lockd/netns.h | 1 + fs/lockd/svc.c | 1 + fs/lockd/svc4proc.c | 2 +- fs/lockd/svcproc.c | 2 +- include/linux/lockd/lockd.h | 9 ++++++--- 7 files changed, 36 insertions(+), 22 deletions(-) diff --git a/fs/lockd/host.c b/fs/lockd/host.c index 969d589c848d..b5f3c3ab0d5f 100644 --- a/fs/lockd/host.c +++ b/fs/lockd/host.c @@ -116,7 +116,7 @@ static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni, atomic_inc(&nsm->sm_count); else { host = NULL; - nsm = nsm_get_handle(ni->sap, ni->salen, + nsm = nsm_get_handle(ni->net, ni->sap, ni->salen, ni->hostname, ni->hostname_len); if (unlikely(nsm == NULL)) { dprintk("lockd: %s failed; no nsm handle\n", @@ -534,17 +534,18 @@ static struct nlm_host *next_host_state(struct hlist_head *cache, /** * nlm_host_rebooted - Release all resources held by rebooted host + * @net: network namespace * @info: pointer to decoded results of NLM_SM_NOTIFY call * * We were notified that the specified host has rebooted. Release * all resources held by that peer. */ -void nlm_host_rebooted(const struct nlm_reboot *info) +void nlm_host_rebooted(const struct net *net, const struct nlm_reboot *info) { struct nsm_handle *nsm; struct nlm_host *host; - nsm = nsm_reboot_lookup(info); + nsm = nsm_reboot_lookup(net, info); if (unlikely(nsm == NULL)) return; diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index 47a32b6d9b90..6c05cd17e520 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -51,7 +51,6 @@ struct nsm_res { }; static const struct rpc_program nsm_program; -static LIST_HEAD(nsm_handles); static DEFINE_SPINLOCK(nsm_lock); /* @@ -264,33 +263,35 @@ void nsm_unmonitor(const struct nlm_host *host) } } -static struct nsm_handle *nsm_lookup_hostname(const char *hostname, - const size_t len) +static struct nsm_handle *nsm_lookup_hostname(const struct list_head *nsm_handles, + const char *hostname, const size_t len) { struct nsm_handle *nsm; - list_for_each_entry(nsm, &nsm_handles, sm_link) + list_for_each_entry(nsm, nsm_handles, sm_link) if (strlen(nsm->sm_name) == len && memcmp(nsm->sm_name, hostname, len) == 0) return nsm; return NULL; } -static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap) +static struct nsm_handle *nsm_lookup_addr(const struct list_head *nsm_handles, + const struct sockaddr *sap) { struct nsm_handle *nsm; - list_for_each_entry(nsm, &nsm_handles, sm_link) + list_for_each_entry(nsm, nsm_handles, sm_link) if (rpc_cmp_addr(nsm_addr(nsm), sap)) return nsm; return NULL; } -static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv) +static struct nsm_handle *nsm_lookup_priv(const struct list_head *nsm_handles, + const struct nsm_private *priv) { struct nsm_handle *nsm; - list_for_each_entry(nsm, &nsm_handles, sm_link) + list_for_each_entry(nsm, nsm_handles, sm_link) if (memcmp(nsm->sm_priv.data, priv->data, sizeof(priv->data)) == 0) return nsm; @@ -353,6 +354,7 @@ static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap, /** * nsm_get_handle - Find or create a cached nsm_handle + * @net: network namespace * @sap: pointer to socket address of handle to find * @salen: length of socket address * @hostname: pointer to C string containing hostname to find @@ -365,11 +367,13 @@ static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap, * @hostname cannot be found in the handle cache. Returns NULL if * an error occurs. */ -struct nsm_handle *nsm_get_handle(const struct sockaddr *sap, +struct nsm_handle *nsm_get_handle(const struct net *net, + const struct sockaddr *sap, const size_t salen, const char *hostname, const size_t hostname_len) { struct nsm_handle *cached, *new = NULL; + struct lockd_net *ln = net_generic(net, lockd_net_id); if (hostname && memchr(hostname, '/', hostname_len) != NULL) { if (printk_ratelimit()) { @@ -384,9 +388,10 @@ retry: spin_lock(&nsm_lock); if (nsm_use_hostnames && hostname != NULL) - cached = nsm_lookup_hostname(hostname, hostname_len); + cached = nsm_lookup_hostname(&ln->nsm_handles, + hostname, hostname_len); else - cached = nsm_lookup_addr(sap); + cached = nsm_lookup_addr(&ln->nsm_handles, sap); if (cached != NULL) { atomic_inc(&cached->sm_count); @@ -400,7 +405,7 @@ retry: } if (new != NULL) { - list_add(&new->sm_link, &nsm_handles); + list_add(&new->sm_link, &ln->nsm_handles); spin_unlock(&nsm_lock); dprintk("lockd: created nsm_handle for %s (%s)\n", new->sm_name, new->sm_addrbuf); @@ -417,19 +422,22 @@ retry: /** * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle + * @net: network namespace * @info: pointer to NLMPROC_SM_NOTIFY arguments * * Returns a matching nsm_handle if found in the nsm cache. The returned * nsm_handle's reference count is bumped. Otherwise returns NULL if some * error occurred. */ -struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info) +struct nsm_handle *nsm_reboot_lookup(const struct net *net, + const struct nlm_reboot *info) { struct nsm_handle *cached; + struct lockd_net *ln = net_generic(net, lockd_net_id); spin_lock(&nsm_lock); - cached = nsm_lookup_priv(&info->priv); + cached = nsm_lookup_priv(&ln->nsm_handles, &info->priv); if (unlikely(cached == NULL)) { spin_unlock(&nsm_lock); dprintk("lockd: never saw rebooted peer '%.*s' before\n", diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h index 097bfa3adb1c..89fe011b1335 100644 --- a/fs/lockd/netns.h +++ b/fs/lockd/netns.h @@ -15,6 +15,7 @@ struct lockd_net { spinlock_t nsm_clnt_lock; unsigned int nsm_users; struct rpc_clnt *nsm_clnt; + struct list_head nsm_handles; }; extern int lockd_net_id; diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index d678bcc3cbcb..0dff13f41808 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -593,6 +593,7 @@ static int lockd_init_net(struct net *net) INIT_LIST_HEAD(&ln->lockd_manager.list); ln->lockd_manager.block_opens = false; spin_lock_init(&ln->nsm_clnt_lock); + INIT_LIST_HEAD(&ln->nsm_handles); return 0; } diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c index b147d1ae71fd..09c576f26c7b 100644 --- a/fs/lockd/svc4proc.c +++ b/fs/lockd/svc4proc.c @@ -421,7 +421,7 @@ nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp, return rpc_system_err; } - nlm_host_rebooted(argp); + nlm_host_rebooted(SVC_NET(rqstp), argp); return rpc_success; } diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c index 21171f0c6477..fb26b9f522e7 100644 --- a/fs/lockd/svcproc.c +++ b/fs/lockd/svcproc.c @@ -464,7 +464,7 @@ nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp, return rpc_system_err; } - nlm_host_rebooted(argp); + nlm_host_rebooted(SVC_NET(rqstp), argp); return rpc_success; } diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h index ff82a32871b5..fd3b65bf51b5 100644 --- a/include/linux/lockd/lockd.h +++ b/include/linux/lockd/lockd.h @@ -235,7 +235,8 @@ void nlm_rebind_host(struct nlm_host *); struct nlm_host * nlm_get_host(struct nlm_host *); void nlm_shutdown_hosts(void); void nlm_shutdown_hosts_net(struct net *net); -void nlm_host_rebooted(const struct nlm_reboot *); +void nlm_host_rebooted(const struct net *net, + const struct nlm_reboot *); /* * Host monitoring @@ -243,11 +244,13 @@ void nlm_host_rebooted(const struct nlm_reboot *); int nsm_monitor(const struct nlm_host *host); void nsm_unmonitor(const struct nlm_host *host); -struct nsm_handle *nsm_get_handle(const struct sockaddr *sap, +struct nsm_handle *nsm_get_handle(const struct net *net, + const struct sockaddr *sap, const size_t salen, const char *hostname, const size_t hostname_len); -struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info); +struct nsm_handle *nsm_reboot_lookup(const struct net *net, + const struct nlm_reboot *info); void nsm_release(struct nsm_handle *nsm); /* -- 2.20.1