[ 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 Salim<jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netdevice_tracker dev_tracker;
struct Qdisc __rcu *qdisc;
- struct Qdisc *qdisc_sleeping;
+ struct Qdisc __rcu *qdisc_sleeping;
#ifdef CONFIG_SYSFS
struct kobject kobj;
#endif
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)
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;
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;
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;
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;
}
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)) {
}
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);
}
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);
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;
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:
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);
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,
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 = {
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);
/* ... 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);
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);
}
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)
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 {
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;
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))
struct Qdisc *qdisc;
bool nolock;
- qdisc = dev_queue->qdisc_sleeping;
+ qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
if (!qdisc)
return;
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);
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)
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.
*/
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);
}
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)
* 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,
{
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)
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;
}
{
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;
* 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,
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)
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;
} 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)
{
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);
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,
{
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,
{
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)
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)
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)
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;
}
{
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;
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)) {