From: Eric Dumazet edumazet@google.com
[ Upstream commit d636fc5dd692c8f4e00ae6e0359c0eceeb5d9bdb ]
syzbot reported a race around qdisc->qdisc_sleeping [1]
It is time we add proper annotations to reads and writes to/from qdisc->qdisc_sleeping.
[1] BUG: KCSAN: data-race in dev_graft_qdisc / qdisc_lookup_rcu
read to 0xffff8881286fc618 of 8 bytes by task 6928 on cpu 1: qdisc_lookup_rcu+0x192/0x2c0 net/sched/sch_api.c:331 __tcf_qdisc_find+0x74/0x3c0 net/sched/cls_api.c:1174 tc_get_tfilter+0x18f/0x990 net/sched/cls_api.c:2547 rtnetlink_rcv_msg+0x7af/0x8c0 net/core/rtnetlink.c:6386 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x375/0x4c0 net/socket.c:2503 ___sys_sendmsg net/socket.c:2557 [inline] __sys_sendmsg+0x1e3/0x270 net/socket.c:2586 __do_sys_sendmsg net/socket.c:2595 [inline] __se_sys_sendmsg net/socket.c:2593 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2593 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
write to 0xffff8881286fc618 of 8 bytes by task 6912 on cpu 0: dev_graft_qdisc+0x4f/0x80 net/sched/sch_generic.c:1115 qdisc_graft+0x7d0/0xb60 net/sched/sch_api.c:1103 tc_modify_qdisc+0x712/0xf10 net/sched/sch_api.c:1693 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6395 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0x375/0x4c0 net/socket.c:2503 ___sys_sendmsg net/socket.c:2557 [inline] __sys_sendmsg+0x1e3/0x270 net/socket.c:2586 __do_sys_sendmsg net/socket.c:2595 [inline] __se_sys_sendmsg net/socket.c:2593 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2593 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 6912 Comm: syz-executor.5 Not tainted 6.4.0-rc3-syzkaller-00190-g0d85b27b0cc6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/16/2023
Fixes: 3a7d0d07a386 ("net: sched: extend Qdisc with rcu") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Cc: Vlad Buslov vladbu@nvidia.com Acked-by: Jamal Hadi Salimjhs@mojatatu.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/netdevice.h | 2 +- include/net/sch_generic.h | 6 ++++-- net/core/dev.c | 2 +- net/sched/sch_api.c | 26 ++++++++++++++++---------- net/sched/sch_fq_pie.c | 2 ++ net/sched/sch_generic.c | 30 +++++++++++++++--------------- net/sched/sch_mq.c | 8 ++++---- net/sched/sch_mqprio.c | 8 ++++---- net/sched/sch_pie.c | 5 ++++- net/sched/sch_red.c | 5 ++++- net/sched/sch_sfq.c | 5 ++++- net/sched/sch_taprio.c | 6 +++--- net/sched/sch_teql.c | 2 +- 13 files changed, 63 insertions(+), 44 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 2771aa046ab2a..7ed63f5bbe056 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -612,7 +612,7 @@ struct netdev_queue { netdevice_tracker dev_tracker;
struct Qdisc __rcu *qdisc; - struct Qdisc *qdisc_sleeping; + struct Qdisc __rcu *qdisc_sleeping; #ifdef CONFIG_SYSFS struct kobject kobj; #endif diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index fab5ba3e61b7c..27271f2b37cb3 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -545,7 +545,7 @@ static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) { - return qdisc->dev_queue->qdisc_sleeping; + return rcu_dereference_rtnl(qdisc->dev_queue->qdisc_sleeping); }
static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) @@ -754,7 +754,9 @@ static inline bool qdisc_tx_changing(const struct net_device *dev)
for (i = 0; i < dev->num_tx_queues; i++) { struct netdev_queue *txq = netdev_get_tx_queue(dev, i); - if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) + + if (rcu_access_pointer(txq->qdisc) != + rcu_access_pointer(txq->qdisc_sleeping)) return true; } return false; diff --git a/net/core/dev.c b/net/core/dev.c index 6d46eb0402ccd..bcb654fd519bd 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10507,7 +10507,7 @@ struct netdev_queue *dev_ingress_queue_create(struct net_device *dev) return NULL; netdev_init_one_queue(dev, queue, NULL); RCU_INIT_POINTER(queue->qdisc, &noop_qdisc); - queue->qdisc_sleeping = &noop_qdisc; + RCU_INIT_POINTER(queue->qdisc_sleeping, &noop_qdisc); rcu_assign_pointer(dev->ingress_queue, queue); #endif return queue; diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 7045b67b5533e..b2a63d697a4aa 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -309,7 +309,7 @@ struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle)
if (dev_ingress_queue(dev)) q = qdisc_match_from_root( - dev_ingress_queue(dev)->qdisc_sleeping, + rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping), handle); out: return q; @@ -328,7 +328,8 @@ struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
nq = dev_ingress_queue_rcu(dev); if (nq) - q = qdisc_match_from_root(nq->qdisc_sleeping, handle); + q = qdisc_match_from_root(rcu_dereference(nq->qdisc_sleeping), + handle); out: return q; } @@ -634,8 +635,13 @@ EXPORT_SYMBOL(qdisc_watchdog_init); void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires, u64 delta_ns) { - if (test_bit(__QDISC_STATE_DEACTIVATED, - &qdisc_root_sleeping(wd->qdisc)->state)) + bool deactivated; + + rcu_read_lock(); + deactivated = test_bit(__QDISC_STATE_DEACTIVATED, + &qdisc_root_sleeping(wd->qdisc)->state); + rcu_read_unlock(); + if (deactivated) return;
if (hrtimer_is_queued(&wd->timer)) { @@ -1476,7 +1482,7 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, } q = qdisc_leaf(p, clid); } else if (dev_ingress_queue(dev)) { - q = dev_ingress_queue(dev)->qdisc_sleeping; + q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); } } else { q = rtnl_dereference(dev->qdisc); @@ -1562,7 +1568,7 @@ static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, } q = qdisc_leaf(p, clid); } else if (dev_ingress_queue_create(dev)) { - q = dev_ingress_queue(dev)->qdisc_sleeping; + q = rtnl_dereference(dev_ingress_queue(dev)->qdisc_sleeping); } } else { q = rtnl_dereference(dev->qdisc); @@ -1803,8 +1809,8 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
dev_queue = dev_ingress_queue(dev); if (dev_queue && - tc_dump_qdisc_root(dev_queue->qdisc_sleeping, skb, cb, - &q_idx, s_q_idx, false, + tc_dump_qdisc_root(rtnl_dereference(dev_queue->qdisc_sleeping), + skb, cb, &q_idx, s_q_idx, false, tca[TCA_DUMP_INVISIBLE]) < 0) goto done;
@@ -2247,8 +2253,8 @@ static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
dev_queue = dev_ingress_queue(dev); if (dev_queue && - tc_dump_tclass_root(dev_queue->qdisc_sleeping, skb, tcm, cb, - &t, s_t, false) < 0) + tc_dump_tclass_root(rtnl_dereference(dev_queue->qdisc_sleeping), + skb, tcm, cb, &t, s_t, false) < 0) goto done;
done: diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index c699e5095607d..591d87d5e5c0f 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -379,6 +379,7 @@ static void fq_pie_timer(struct timer_list *t) spinlock_t *root_lock; /* to lock qdisc for probability calculations */ u32 idx;
+ rcu_read_lock(); root_lock = qdisc_lock(qdisc_root_sleeping(sch)); spin_lock(root_lock);
@@ -391,6 +392,7 @@ static void fq_pie_timer(struct timer_list *t) mod_timer(&q->adapt_timer, jiffies + q->p_params.tupdate);
spin_unlock(root_lock); + rcu_read_unlock(); }
static int fq_pie_init(struct Qdisc *sch, struct nlattr *opt, diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index a9aadc4e68581..ee43e8ac039ed 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -648,7 +648,7 @@ struct Qdisc_ops noop_qdisc_ops __read_mostly = {
static struct netdev_queue noop_netdev_queue = { RCU_POINTER_INITIALIZER(qdisc, &noop_qdisc), - .qdisc_sleeping = &noop_qdisc, + RCU_POINTER_INITIALIZER(qdisc_sleeping, &noop_qdisc), };
struct Qdisc noop_qdisc = { @@ -1103,7 +1103,7 @@ EXPORT_SYMBOL(qdisc_put_unlocked); struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, struct Qdisc *qdisc) { - struct Qdisc *oqdisc = dev_queue->qdisc_sleeping; + struct Qdisc *oqdisc = rtnl_dereference(dev_queue->qdisc_sleeping); spinlock_t *root_lock;
root_lock = qdisc_lock(oqdisc); @@ -1112,7 +1112,7 @@ struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, /* ... and graft new one */ if (qdisc == NULL) qdisc = &noop_qdisc; - dev_queue->qdisc_sleeping = qdisc; + rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc); rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
spin_unlock_bh(root_lock); @@ -1125,12 +1125,12 @@ static void shutdown_scheduler_queue(struct net_device *dev, struct netdev_queue *dev_queue, void *_qdisc_default) { - struct Qdisc *qdisc = dev_queue->qdisc_sleeping; + struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping); struct Qdisc *qdisc_default = _qdisc_default;
if (qdisc) { rcu_assign_pointer(dev_queue->qdisc, qdisc_default); - dev_queue->qdisc_sleeping = qdisc_default; + rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc_default);
qdisc_put(qdisc); } @@ -1154,7 +1154,7 @@ static void attach_one_default_qdisc(struct net_device *dev,
if (!netif_is_multiqueue(dev)) qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT; - dev_queue->qdisc_sleeping = qdisc; + rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc); }
static void attach_default_qdiscs(struct net_device *dev) @@ -1167,7 +1167,7 @@ static void attach_default_qdiscs(struct net_device *dev) if (!netif_is_multiqueue(dev) || dev->priv_flags & IFF_NO_QUEUE) { netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL); - qdisc = txq->qdisc_sleeping; + qdisc = rtnl_dereference(txq->qdisc_sleeping); rcu_assign_pointer(dev->qdisc, qdisc); qdisc_refcount_inc(qdisc); } else { @@ -1186,7 +1186,7 @@ static void attach_default_qdiscs(struct net_device *dev) netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc); dev->priv_flags |= IFF_NO_QUEUE; netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL); - qdisc = txq->qdisc_sleeping; + qdisc = rtnl_dereference(txq->qdisc_sleeping); rcu_assign_pointer(dev->qdisc, qdisc); qdisc_refcount_inc(qdisc); dev->priv_flags ^= IFF_NO_QUEUE; @@ -1202,7 +1202,7 @@ static void transition_one_qdisc(struct net_device *dev, struct netdev_queue *dev_queue, void *_need_watchdog) { - struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping; + struct Qdisc *new_qdisc = rtnl_dereference(dev_queue->qdisc_sleeping); int *need_watchdog_p = _need_watchdog;
if (!(new_qdisc->flags & TCQ_F_BUILTIN)) @@ -1272,7 +1272,7 @@ static void dev_reset_queue(struct net_device *dev, struct Qdisc *qdisc; bool nolock;
- qdisc = dev_queue->qdisc_sleeping; + qdisc = rtnl_dereference(dev_queue->qdisc_sleeping); if (!qdisc) return;
@@ -1303,7 +1303,7 @@ static bool some_qdisc_is_busy(struct net_device *dev) int val;
dev_queue = netdev_get_tx_queue(dev, i); - q = dev_queue->qdisc_sleeping; + q = rtnl_dereference(dev_queue->qdisc_sleeping);
root_lock = qdisc_lock(q); spin_lock_bh(root_lock); @@ -1379,7 +1379,7 @@ EXPORT_SYMBOL(dev_deactivate); static int qdisc_change_tx_queue_len(struct net_device *dev, struct netdev_queue *dev_queue) { - struct Qdisc *qdisc = dev_queue->qdisc_sleeping; + struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping); const struct Qdisc_ops *ops = qdisc->ops;
if (ops->change_tx_queue_len) @@ -1404,7 +1404,7 @@ void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx) unsigned int i;
for (i = new_real_tx; i < dev->real_num_tx_queues; i++) { - qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping; + qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc_sleeping); /* Only update the default qdiscs we created, * qdiscs with handles are always hashed. */ @@ -1412,7 +1412,7 @@ void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx) qdisc_hash_del(qdisc); } for (i = dev->real_num_tx_queues; i < new_real_tx; i++) { - qdisc = netdev_get_tx_queue(dev, i)->qdisc_sleeping; + qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc_sleeping); if (qdisc != &noop_qdisc && !qdisc->handle) qdisc_hash_add(qdisc, false); } @@ -1449,7 +1449,7 @@ static void dev_init_scheduler_queue(struct net_device *dev, struct Qdisc *qdisc = _qdisc;
rcu_assign_pointer(dev_queue->qdisc, qdisc); - dev_queue->qdisc_sleeping = qdisc; + rcu_assign_pointer(dev_queue->qdisc_sleeping, qdisc); }
void dev_init_scheduler(struct net_device *dev) diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c index d0bc660d7401f..c860119a8f091 100644 --- a/net/sched/sch_mq.c +++ b/net/sched/sch_mq.c @@ -141,7 +141,7 @@ static int mq_dump(struct Qdisc *sch, struct sk_buff *skb) * qdisc totals are added at end. */ for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { - qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; + qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping); spin_lock_bh(qdisc_lock(qdisc));
gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats, @@ -202,7 +202,7 @@ static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl) { struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
- return dev_queue->qdisc_sleeping; + return rtnl_dereference(dev_queue->qdisc_sleeping); }
static unsigned long mq_find(struct Qdisc *sch, u32 classid) @@ -221,7 +221,7 @@ static int mq_dump_class(struct Qdisc *sch, unsigned long cl,
tcm->tcm_parent = TC_H_ROOT; tcm->tcm_handle |= TC_H_MIN(cl); - tcm->tcm_info = dev_queue->qdisc_sleeping->handle; + tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle; return 0; }
@@ -230,7 +230,7 @@ static int mq_dump_class_stats(struct Qdisc *sch, unsigned long cl, { struct netdev_queue *dev_queue = mq_queue_get(sch, cl);
- sch = dev_queue->qdisc_sleeping; + sch = rtnl_dereference(dev_queue->qdisc_sleeping); if (gnet_stats_copy_basic(d, sch->cpu_bstats, &sch->bstats, true) < 0 || qdisc_qstats_copy(d, sch) < 0) return -1; diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c index fc6225f15fcdb..dd29c9470c784 100644 --- a/net/sched/sch_mqprio.c +++ b/net/sched/sch_mqprio.c @@ -421,7 +421,7 @@ static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) * qdisc totals are added at end. */ for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { - qdisc = netdev_get_tx_queue(dev, ntx)->qdisc_sleeping; + qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping); spin_lock_bh(qdisc_lock(qdisc));
gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats, @@ -465,7 +465,7 @@ static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl) if (!dev_queue) return NULL;
- return dev_queue->qdisc_sleeping; + return rtnl_dereference(dev_queue->qdisc_sleeping); }
static unsigned long mqprio_find(struct Qdisc *sch, u32 classid) @@ -498,7 +498,7 @@ static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl, tcm->tcm_parent = (tc < 0) ? 0 : TC_H_MAKE(TC_H_MAJ(sch->handle), TC_H_MIN(tc + TC_H_MIN_PRIORITY)); - tcm->tcm_info = dev_queue->qdisc_sleeping->handle; + tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle; } else { tcm->tcm_parent = TC_H_ROOT; tcm->tcm_info = 0; @@ -554,7 +554,7 @@ static int mqprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, } else { struct netdev_queue *dev_queue = mqprio_queue_get(sch, cl);
- sch = dev_queue->qdisc_sleeping; + sch = rtnl_dereference(dev_queue->qdisc_sleeping); if (gnet_stats_copy_basic(d, sch->cpu_bstats, &sch->bstats, true) < 0 || qdisc_qstats_copy(d, sch) < 0) diff --git a/net/sched/sch_pie.c b/net/sched/sch_pie.c index 265c238047a42..b60b31ef71cc5 100644 --- a/net/sched/sch_pie.c +++ b/net/sched/sch_pie.c @@ -421,8 +421,10 @@ static void pie_timer(struct timer_list *t) { struct pie_sched_data *q = from_timer(q, t, adapt_timer); struct Qdisc *sch = q->sch; - spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); + spinlock_t *root_lock;
+ rcu_read_lock(); + root_lock = qdisc_lock(qdisc_root_sleeping(sch)); spin_lock(root_lock); pie_calculate_probability(&q->params, &q->vars, sch->qstats.backlog);
@@ -430,6 +432,7 @@ static void pie_timer(struct timer_list *t) if (q->params.tupdate) mod_timer(&q->adapt_timer, jiffies + q->params.tupdate); spin_unlock(root_lock); + rcu_read_unlock(); }
static int pie_init(struct Qdisc *sch, struct nlattr *opt, diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c index 98129324e1573..16277b6a0238d 100644 --- a/net/sched/sch_red.c +++ b/net/sched/sch_red.c @@ -321,12 +321,15 @@ static inline void red_adaptative_timer(struct timer_list *t) { struct red_sched_data *q = from_timer(q, t, adapt_timer); struct Qdisc *sch = q->sch; - spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); + spinlock_t *root_lock;
+ rcu_read_lock(); + root_lock = qdisc_lock(qdisc_root_sleeping(sch)); spin_lock(root_lock); red_adaptative_algo(&q->parms, &q->vars); mod_timer(&q->adapt_timer, jiffies + HZ/2); spin_unlock(root_lock); + rcu_read_unlock(); }
static int red_init(struct Qdisc *sch, struct nlattr *opt, diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c index abd436307d6a8..66dcb18638fea 100644 --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -606,10 +606,12 @@ static void sfq_perturbation(struct timer_list *t) { struct sfq_sched_data *q = from_timer(q, t, perturb_timer); struct Qdisc *sch = q->sch; - spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); + spinlock_t *root_lock; siphash_key_t nkey;
get_random_bytes(&nkey, sizeof(nkey)); + rcu_read_lock(); + root_lock = qdisc_lock(qdisc_root_sleeping(sch)); spin_lock(root_lock); q->perturbation = nkey; if (!q->filter_list && q->tail) @@ -618,6 +620,7 @@ static void sfq_perturbation(struct timer_list *t)
if (q->perturb_period) mod_timer(&q->perturb_timer, jiffies + q->perturb_period); + rcu_read_unlock(); }
static int sfq_change(struct Qdisc *sch, struct nlattr *opt) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index cbad430191721..a6cf56a969421 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -2319,7 +2319,7 @@ static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl) if (!dev_queue) return NULL;
- return dev_queue->qdisc_sleeping; + return rtnl_dereference(dev_queue->qdisc_sleeping); }
static unsigned long taprio_find(struct Qdisc *sch, u32 classid) @@ -2338,7 +2338,7 @@ static int taprio_dump_class(struct Qdisc *sch, unsigned long cl,
tcm->tcm_parent = TC_H_ROOT; tcm->tcm_handle |= TC_H_MIN(cl); - tcm->tcm_info = dev_queue->qdisc_sleeping->handle; + tcm->tcm_info = rtnl_dereference(dev_queue->qdisc_sleeping)->handle;
return 0; } @@ -2350,7 +2350,7 @@ static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl, { struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
- sch = dev_queue->qdisc_sleeping; + sch = rtnl_dereference(dev_queue->qdisc_sleeping); if (gnet_stats_copy_basic(d, NULL, &sch->bstats, true) < 0 || qdisc_qstats_copy(d, sch) < 0) return -1; diff --git a/net/sched/sch_teql.c b/net/sched/sch_teql.c index 16f9238aa51d1..7721239c185fb 100644 --- a/net/sched/sch_teql.c +++ b/net/sched/sch_teql.c @@ -297,7 +297,7 @@ static netdev_tx_t teql_master_xmit(struct sk_buff *skb, struct net_device *dev) struct net_device *slave = qdisc_dev(q); struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
- if (slave_txq->qdisc_sleeping != q) + if (rcu_access_pointer(slave_txq->qdisc_sleeping) != q) continue; if (netif_xmit_stopped(netdev_get_tx_queue(slave, subq)) || !netif_running(slave)) {