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authorEric Dumazet <edumazet@google.com>2023-06-06 11:19:29 +0000
committerDavid S. Miller <davem@davemloft.net>2023-06-07 10:25:39 +0100
commitd636fc5dd692c8f4e00ae6e0359c0eceeb5d9bdb (patch)
treee09b16c0b8f6b4d9025c918c1db387454fd8c84f /include
parente3144ff52f7d2c884eef352cec9b9ff9acd2eb2f (diff)
net: sched: add rcu annotations around qdisc->qdisc_sleeping
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>
Diffstat (limited to 'include')
-rw-r--r--include/linux/netdevice.h2
-rw-r--r--include/net/sch_generic.h6
2 files changed, 5 insertions, 3 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e6f22b7403d0..c2f0c6002a84 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -620,7 +620,7 @@ 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 fab5ba3e61b7..27271f2b37cb 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;