From 15dacf880e49ce3ecee05eb1a0c6b8e363dbacdc Mon Sep 17 00:00:00 2001 From: "mhiramat@kernel.org" Date: Mon, 15 Aug 2016 18:40:57 +0900 Subject: [PATCH] brcmfmac: Check rtnl_lock is locked when removing interface MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Check rtnl_lock is locked in brcmf_p2p_ifp_removed() by passing rtnl_locked flag. Actually the caller brcmf_del_if() checks whether the rtnl_lock is locked, but doesn't pass it to brcmf_p2p_ifp_removed(). Without this fix, wpa_supplicant goes softlockup with rtnl_lock holding (this means all other process using netlink are locked up too) e.g. [ 4495.876627] INFO: task wpa_supplicant:7307 blocked for more than 10 seconds. [ 4495.876632] Tainted: G W 4.8.0-rc1+ #8 [ 4495.876635] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4495.876638] wpa_supplicant D ffff974c647b39a0 0 7307 1 0x00000000 [ 4495.876644] ffff974c647b39a0 0000000000000000 ffff974c00000000 ffff974c7dc59c58 [ 4495.876651] ffff974c6b7417c0 ffff974c645017c0 ffff974c647b4000 ffffffff86f16c08 [ 4495.876657] ffff974c645017c0 0000000000000246 00000000ffffffff ffff974c647b39b8 [ 4495.876664] Call Trace: [ 4495.876671] [] schedule+0x3c/0x90 [ 4495.876676] [] schedule_preempt_disabled+0x15/0x20 [ 4495.876682] [] mutex_lock_nested+0x176/0x3b0 [ 4495.876686] [] ? rtnl_lock+0x17/0x20 [ 4495.876690] [] rtnl_lock+0x17/0x20 [ 4495.876720] [] brcmf_p2p_ifp_removed+0x4d/0x70 [brcmfmac] [ 4495.876741] [] brcmf_remove_interface+0x196/0x1b0 [brcmfmac] [ 4495.876760] [] brcmf_p2p_del_vif+0x111/0x220 [brcmfmac] [ 4495.876777] [] brcmf_cfg80211_del_iface+0x21b/0x270 [brcmfmac] [ 4495.876820] [] nl80211_del_interface+0xfe/0x3a0 [cfg80211] [ 4495.876825] [] genl_family_rcv_msg+0x1b5/0x370 [ 4495.876832] [] ? trace_hardirqs_on+0xd/0x10 [ 4495.876836] [] genl_rcv_msg+0x7d/0xb0 [ 4495.876839] [] ? genl_family_rcv_msg+0x370/0x370 [ 4495.876846] [] netlink_rcv_skb+0x97/0xb0 [ 4495.876849] [] genl_rcv+0x28/0x40 [ 4495.876854] [] netlink_unicast+0x1d3/0x2f0 [ 4495.876860] [] ? netlink_unicast+0x14b/0x2f0 [ 4495.876866] [] netlink_sendmsg+0x2eb/0x3a0 [ 4495.876870] [] sock_sendmsg+0x38/0x50 [ 4495.876874] [] ___sys_sendmsg+0x27f/0x290 [ 4495.876882] [] ? mntput_no_expire+0x5/0x3f0 [ 4495.876888] [] ? mntput_no_expire+0x8e/0x3f0 [ 4495.876894] [] ? mntput_no_expire+0x5/0x3f0 [ 4495.876899] [] ? mntput+0x24/0x40 [ 4495.876904] [] ? __fput+0x190/0x200 [ 4495.876909] [] __sys_sendmsg+0x45/0x80 [ 4495.876914] [] SyS_sendmsg+0x12/0x20 [ 4495.876918] [] entry_SYSCALL_64_fastpath+0x23/0xc1 [ 4495.876924] [] ? trace_hardirqs_off_caller+0x1f/0xc0 Signed-off-by: Masami Hiramatsu Acked-by: Rafał Miłecki Signed-off-by: Kalle Valo --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c | 2 +- drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c | 8 +++++--- drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.h | 2 +- 3 files changed, 7 insertions(+), 5 deletions(-) --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c @@ -743,7 +743,7 @@ static void brcmf_del_if(struct brcmf_pu * serious troublesome side effects. The p2p module will clean * up the ifp if needed. */ - brcmf_p2p_ifp_removed(ifp); + brcmf_p2p_ifp_removed(ifp, rtnl_locked); kfree(ifp); } } --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c @@ -2299,7 +2299,7 @@ int brcmf_p2p_del_vif(struct wiphy *wiph return err; } -void brcmf_p2p_ifp_removed(struct brcmf_if *ifp) +void brcmf_p2p_ifp_removed(struct brcmf_if *ifp, bool rtnl_locked) { struct brcmf_cfg80211_info *cfg; struct brcmf_cfg80211_vif *vif; @@ -2308,9 +2308,11 @@ void brcmf_p2p_ifp_removed(struct brcmf_ vif = ifp->vif; cfg = wdev_to_cfg(&vif->wdev); cfg->p2p.bss_idx[P2PAPI_BSSCFG_DEVICE].vif = NULL; - rtnl_lock(); + if (!rtnl_locked) + rtnl_lock(); cfg80211_unregister_wdev(&vif->wdev); - rtnl_unlock(); + if (!rtnl_locked) + rtnl_unlock(); brcmf_free_vif(vif); } --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.h +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.h @@ -155,7 +155,7 @@ struct wireless_dev *brcmf_p2p_add_vif(s int brcmf_p2p_del_vif(struct wiphy *wiphy, struct wireless_dev *wdev); int brcmf_p2p_ifchange(struct brcmf_cfg80211_info *cfg, enum brcmf_fil_p2p_if_types if_type); -void brcmf_p2p_ifp_removed(struct brcmf_if *ifp); +void brcmf_p2p_ifp_removed(struct brcmf_if *ifp, bool rtnl_locked); int brcmf_p2p_start_device(struct wiphy *wiphy, struct wireless_dev *wdev); void brcmf_p2p_stop_device(struct wiphy *wiphy, struct wireless_dev *wdev); int brcmf_p2p_scan_prep(struct wiphy *wiphy,