package/kernel/mac80211/patches/319-0012-brcmfmac-Check-rtnl_lock-is-locked-when-removing-int.patch

   1 From 15dacf880e49ce3ecee05eb1a0c6b8e363dbacdc Mon Sep 17 00:00:00 2001
   2 From: "mhiramat@kernel.org" <mhiramat@kernel.org>
   3 Date: Mon, 15 Aug 2016 18:40:57 +0900
   4 Subject: [PATCH] brcmfmac: Check rtnl_lock is locked when removing interface
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Check rtnl_lock is locked in brcmf_p2p_ifp_removed() by passing
  10 rtnl_locked flag. Actually the caller brcmf_del_if() checks whether
  11 the rtnl_lock is locked, but doesn't pass it to brcmf_p2p_ifp_removed().
  12
  13 Without this fix, wpa_supplicant goes softlockup with rtnl_lock
  14 holding (this means all other process using netlink are locked up too)
  15
  16 e.g.
  17 [ 4495.876627] INFO: task wpa_supplicant:7307 blocked for more than 10 seconds.
  18 [ 4495.876632]       Tainted: G        W       4.8.0-rc1+ #8
  19 [ 4495.876635] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  20 [ 4495.876638] wpa_supplicant  D ffff974c647b39a0     0  7307      1 0x00000000
  21 [ 4495.876644]  ffff974c647b39a0 0000000000000000 ffff974c00000000 ffff974c7dc59c58
  22 [ 4495.876651]  ffff974c6b7417c0 ffff974c645017c0 ffff974c647b4000 ffffffff86f16c08
  23 [ 4495.876657]  ffff974c645017c0 0000000000000246 00000000ffffffff ffff974c647b39b8
  24 [ 4495.876664] Call Trace:
  25 [ 4495.876671]  [<ffffffff868aeccc>] schedule+0x3c/0x90
  26 [ 4495.876676]  [<ffffffff868af065>] schedule_preempt_disabled+0x15/0x20
  27 [ 4495.876682]  [<ffffffff868b0996>] mutex_lock_nested+0x176/0x3b0
  28 [ 4495.876686]  [<ffffffff867a2067>] ? rtnl_lock+0x17/0x20
  29 [ 4495.876690]  [<ffffffff867a2067>] rtnl_lock+0x17/0x20
  30 [ 4495.876720]  [<ffffffffc0ae9a5d>] brcmf_p2p_ifp_removed+0x4d/0x70 [brcmfmac]
  31 [ 4495.876741]  [<ffffffffc0aebde6>] brcmf_remove_interface+0x196/0x1b0 [brcmfmac]
  32 [ 4495.876760]  [<ffffffffc0ae9901>] brcmf_p2p_del_vif+0x111/0x220 [brcmfmac]
  33 [ 4495.876777]  [<ffffffffc0adefab>] brcmf_cfg80211_del_iface+0x21b/0x270 [brcmfmac]
  34 [ 4495.876820]  [<ffffffffc097b39e>] nl80211_del_interface+0xfe/0x3a0 [cfg80211]
  35 [ 4495.876825]  [<ffffffff867ca335>] genl_family_rcv_msg+0x1b5/0x370
  36 [ 4495.876832]  [<ffffffff860e5d8d>] ? trace_hardirqs_on+0xd/0x10
  37 [ 4495.876836]  [<ffffffff867ca56d>] genl_rcv_msg+0x7d/0xb0
  38 [ 4495.876839]  [<ffffffff867ca4f0>] ? genl_family_rcv_msg+0x370/0x370
  39 [ 4495.876846]  [<ffffffff867c9a47>] netlink_rcv_skb+0x97/0xb0
  40 [ 4495.876849]  [<ffffffff867ca168>] genl_rcv+0x28/0x40
  41 [ 4495.876854]  [<ffffffff867c93c3>] netlink_unicast+0x1d3/0x2f0
  42 [ 4495.876860]  [<ffffffff867c933b>] ? netlink_unicast+0x14b/0x2f0
  43 [ 4495.876866]  [<ffffffff867c97cb>] netlink_sendmsg+0x2eb/0x3a0
  44 [ 4495.876870]  [<ffffffff8676dad8>] sock_sendmsg+0x38/0x50
  45 [ 4495.876874]  [<ffffffff8676e4df>] ___sys_sendmsg+0x27f/0x290
  46 [ 4495.876882]  [<ffffffff8628b935>] ? mntput_no_expire+0x5/0x3f0
  47 [ 4495.876888]  [<ffffffff8628b9be>] ? mntput_no_expire+0x8e/0x3f0
  48 [ 4495.876894]  [<ffffffff8628b935>] ? mntput_no_expire+0x5/0x3f0
  49 [ 4495.876899]  [<ffffffff8628bd44>] ? mntput+0x24/0x40
  50 [ 4495.876904]  [<ffffffff86267830>] ? __fput+0x190/0x200
  51 [ 4495.876909]  [<ffffffff8676f125>] __sys_sendmsg+0x45/0x80
  52 [ 4495.876914]  [<ffffffff8676f172>] SyS_sendmsg+0x12/0x20
  53 [ 4495.876918]  [<ffffffff868b5680>] entry_SYSCALL_64_fastpath+0x23/0xc1
  54 [ 4495.876924]  [<ffffffff860e2b8f>] ? trace_hardirqs_off_caller+0x1f/0xc0
  55
  56 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
  57 Acked-by: Rafał Miłecki <rafal@milecki.pl>
  58 Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
  59 ---
  60  drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c | 2 +-
  61  drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c  | 8 +++++---
  62  drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.h  | 2 +-
  63  3 files changed, 7 insertions(+), 5 deletions(-)
  64
  65 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
  66 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
  67 @@ -743,7 +743,7 @@ static void brcmf_del_if(struct brcmf_pu
  68                  * serious troublesome side effects. The p2p module will clean
  69                  * up the ifp if needed.
  70                  */
  71 -               brcmf_p2p_ifp_removed(ifp);
  72 +               brcmf_p2p_ifp_removed(ifp, rtnl_locked);
  73                 kfree(ifp);
  74         }
  75  }
  76 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
  77 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
  78 @@ -2299,7 +2299,7 @@ int brcmf_p2p_del_vif(struct wiphy *wiph
  79         return err;
  80  }
  81
  82 -void brcmf_p2p_ifp_removed(struct brcmf_if *ifp)
  83 +void brcmf_p2p_ifp_removed(struct brcmf_if *ifp, bool rtnl_locked)
  84  {
  85         struct brcmf_cfg80211_info *cfg;
  86         struct brcmf_cfg80211_vif *vif;
  87 @@ -2308,9 +2308,11 @@ void brcmf_p2p_ifp_removed(struct brcmf_
  88         vif = ifp->vif;
  89         cfg = wdev_to_cfg(&vif->wdev);
  90         cfg->p2p.bss_idx[P2PAPI_BSSCFG_DEVICE].vif = NULL;
  91 -       rtnl_lock();
  92 +       if (!rtnl_locked)
  93 +               rtnl_lock();
  94         cfg80211_unregister_wdev(&vif->wdev);
  95 -       rtnl_unlock();
  96 +       if (!rtnl_locked)
  97 +               rtnl_unlock();
  98         brcmf_free_vif(vif);
  99  }
 100
 101 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.h
 102 +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.h
 103 @@ -155,7 +155,7 @@ struct wireless_dev *brcmf_p2p_add_vif(s
 104  int brcmf_p2p_del_vif(struct wiphy *wiphy, struct wireless_dev *wdev);
 105  int brcmf_p2p_ifchange(struct brcmf_cfg80211_info *cfg,
 106                        enum brcmf_fil_p2p_if_types if_type);
 107 -void brcmf_p2p_ifp_removed(struct brcmf_if *ifp);
 108 +void brcmf_p2p_ifp_removed(struct brcmf_if *ifp, bool rtnl_locked);
 109  int brcmf_p2p_start_device(struct wiphy *wiphy, struct wireless_dev *wdev);
 110  void brcmf_p2p_stop_device(struct wiphy *wiphy, struct wireless_dev *wdev);
 111  int brcmf_p2p_scan_prep(struct wiphy *wiphy,