| Message ID | 1640147146-4294-1-git-send-email-baowen.zheng@corigine.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 963178a06352a059c688eb36f1f8c2f03212b60b |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v1] flow_offload: fix suspicious RCU usage when offloading tc action | expand |
Hello: This patch was applied to netdev/net-next.git (master) by David S. Miller <davem@davemloft.net>: On Wed, 22 Dec 2021 12:25:46 +0800 you wrote: > Fix suspicious rcu_dereference_protected() usage when offloading tc action. > > We should hold tcfa_lock to offload tc action in action initiation. > > Without these changes, the following warning will be observed: > > WARNING: suspicious RCU usage > 5.16.0-rc5-net-next-01504-g7d1f236dcffa-dirty #50 Tainted: G I > > [...] Here is the summary with links: - [net-next,v1] flow_offload: fix suspicious RCU usage when offloading tc action https://git.kernel.org/netdev/net-next/c/963178a06352 You are awesome, thank you!
diff --git a/net/sched/act_api.c b/net/sched/act_api.c index b2f8a39..32563ce 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -186,12 +186,19 @@ static int offload_action_init(struct flow_offload_action *fl_action, enum offload_act_command cmd, struct netlink_ext_ack *extack) { + int err; + fl_action->extack = extack; fl_action->command = cmd; fl_action->index = act->tcfa_index; - if (act->ops->offload_act_setup) - return act->ops->offload_act_setup(act, fl_action, NULL, false); + if (act->ops->offload_act_setup) { + spin_lock_bh(&act->tcfa_lock); + err = act->ops->offload_act_setup(act, fl_action, NULL, + false); + spin_unlock_bh(&act->tcfa_lock); + return err; + } return -EOPNOTSUPP; }
Fix suspicious rcu_dereference_protected() usage when offloading tc action. We should hold tcfa_lock to offload tc action in action initiation. Without these changes, the following warning will be observed: WARNING: suspicious RCU usage 5.16.0-rc5-net-next-01504-g7d1f236dcffa-dirty #50 Tainted: G I ----------------------------- include/net/tc_act/tc_tunnel_key.h:33 suspicious rcu_dereference_protected() usage! 1 lock held by tc/12108: CPU: 4 PID: 12108 Comm: tc Tainted: G Hardware name: Dell Inc. PowerEdge R740/07WCGN, BIOS 1.6.11 11/20/2018 Call Trace: <TASK> dump_stack_lvl+0x49/0x5e dump_stack+0x10/0x12 lockdep_rcu_suspicious+0xed/0xf8 tcf_tunnel_key_offload_act_setup+0x1de/0x300 [act_tunnel_key] tcf_action_offload_add_ex+0xc0/0x1f0 tcf_action_init+0x26a/0x2f0 tcf_action_add+0xa9/0x1f0 tc_ctl_action+0xfb/0x170 rtnetlink_rcv_msg+0x169/0x510 ? sched_clock+0x9/0x10 ? rtnl_newlink+0x70/0x70 netlink_rcv_skb+0x55/0x100 rtnetlink_rcv+0x15/0x20 netlink_unicast+0x1a8/0x270 netlink_sendmsg+0x245/0x490 sock_sendmsg+0x65/0x70 ____sys_sendmsg+0x219/0x260 ? __import_iovec+0x2c/0x150 ___sys_sendmsg+0xb7/0x100 ? __lock_acquire+0x3d5/0x1f40 ? __this_cpu_preempt_check+0x13/0x20 ? lock_is_held_type+0xe4/0x140 ? sched_clock+0x9/0x10 ? ktime_get_coarse_real_ts64+0xbe/0xd0 ? __this_cpu_preempt_check+0x13/0x20 ? lockdep_hardirqs_on+0x7e/0x100 ? ktime_get_coarse_real_ts64+0xbe/0xd0 ? trace_hardirqs_on+0x2a/0xf0 __sys_sendmsg+0x5a/0xa0 ? syscall_trace_enter.constprop.0+0x1dd/0x220 __x64_sys_sendmsg+0x1f/0x30 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4db7bb7a60 Fixes: 8cbfe939abe9 ("flow_offload: allow user to offload tc action to net device") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Louis Peens <louis.peens@corigine.com> --- net/sched/act_api.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)