On pre-emption enabled kernels the following oops was being seen due to missing local_bh_disable/local_bh_enable calls. mac80211 assumes that pre-emption is disabled in the data path. [ 5365.229756] Call Trace: [ 5365.229762] dump_stack+0x5c/0x80 [ 5365.229766] check_preemption_disabled.cold.0+0x46/0x51 [ 5365.229779] __ieee80211_subif_start_xmit+0x144/0x210 [mac80211] [ 5365.229790] ieee80211_tx_control_port+0x116/0x140 [mac80211] [ 5365.229806] nl80211_tx_control_port+0x13c/0x270 [cfg80211] [ 5365.229810] genl_family_rcv_msg+0x1c4/0x3a0 [ 5365.229814] ? nlmon_xmit+0x3c/0x50 [nlmon] [ 5365.229816] ? dev_hard_start_xmit+0xa5/0x240 [ 5365.229817] genl_rcv_msg+0x47/0x90 [ 5365.229818] ? genl_family_rcv_msg+0x3a0/0x3a0 [ 5365.229820] netlink_rcv_skb+0x4c/0x120 [ 5365.229821] genl_rcv+0x24/0x40 [ 5365.229822] netlink_unicast+0x196/0x240 [ 5365.229824] netlink_sendmsg+0x1fd/0x3c0 [ 5365.229826] sock_sendmsg+0x33/0x40 [ 5365.229827] __sys_sendto+0xee/0x160 [ 5365.229830] ? __se_sys_epoll_ctl+0x34d/0xe80 [ 5365.229831] ? do_epoll_wait+0xb0/0xd0 [ 5365.229832] __x64_sys_sendto+0x24/0x30 [ 5365.229835] do_syscall_64+0x5b/0x170 [ 5365.229836] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Denis Kenzior <denkenz@xxxxxxxxx> --- net/mac80211/tx.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 5b93bde248fd..6a79d564de35 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -4850,7 +4850,9 @@ int ieee80211_tx_control_port(struct wiphy *wiphy, struct net_device *dev, skb_reset_network_header(skb); skb_reset_mac_header(skb); + local_bh_disable(); __ieee80211_subif_start_xmit(skb, skb->dev, flags); + local_bh_enable(); return 0; } -- 2.13.5
