package/kernel/mac80211/patches/322-brcmfmac-only-call-brcmf_cfg80211_detach-when-attach.patch

   1 From: Arend van Spriel <arend@broadcom.com>
   2 Date: Wed, 26 Aug 2015 22:14:56 +0200
   3 Subject: [PATCH] brcmfmac: only call brcmf_cfg80211_detach() when attach
   4  was successful
   5
   6 In brcmf_bus_start() the function brcmf_cfg80211_attach() is called which
   7 may fail. If this happens we should not call brcmf_cfg80211_detach() in
   8 the failure path as it will result in NULL pointer dereference:
   9
  10   brcmf_fweh_activate_events: Set event_msgs error (-5)
  11   brcmf_bus_start: failed: -5
  12   brcmf_sdio_firmware_callback: dongle is not responding
  13   BUG: unable to handle kernel NULL pointer dereference at 0000000000000068
  14   IP: [<ffffffff811e8f08>] kernfs_find_ns+0x18/0xd0
  15   PGD 0
  16   Oops: 0000 [#1] SMP
  17   Modules linked in: brcmfmac(O) brcmutil(O) cfg80211 auth_rpcgss
  18   CPU: 1 PID: 45 Comm: kworker/1:1 Tainted: G           O
  19   Hardware name: Dell Inc. Latitude E6410/07XJP9, BIOS A07 02/15/2011
  20   Workqueue: events request_firmware_work_func
  21   task: ffff880036c09ac0 ti: ffff880036dd4000 task.ti: ffff880036dd4000
  22   RIP: 0010:[<ffffffff811e8f08>]  [<ffffffff811e8f08>] kernfs_find_ns+0x18/0xd0
  23   RSP: 0018:ffff880036dd7a28  EFLAGS: 00010246
  24   RAX: ffff880036c09ac0 RBX: 0000000000000000 RCX: 000000007fffffff
  25   RDX: 0000000000000000 RSI: ffffffff816578b9 RDI: 0000000000000000
  26   RBP: ffff880036dd7a48 R08: 0000000000000000 R09: ffff880036c0b340
  27   R10: 00000000000002ec R11: ffff880036dd7b08 R12: ffffffff816578b9
  28   R13: 0000000000000000 R14: ffffffff816578b9 R15: ffff8800c6c87000
  29   FS:  0000000000000000(0000) GS:ffff88012bc40000(0000) knlGS:0000000000000000
  30   CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  31   CR2: 0000000000000068 CR3: 0000000001a0b000 CR4: 00000000000006e0
  32   Stack:
  33    0000000000000000 ffffffff816578b9 0000000000000000 ffff8800c0d003c8
  34    ffff880036dd7a78 ffffffff811e8ff5 0000000ffffffff1 ffffffff81a9b060
  35    ffff8800c789f880 ffff8800c0d00000 ffff880036dd7a98 ffffffff811ebe0d
  36   Call Trace:
  37    [<ffffffff811e8ff5>] kernfs_find_and_get_ns+0x35/0x60
  38    [<ffffffff811ebe0d>] sysfs_unmerge_group+0x1d/0x60
  39    [<ffffffff81404ef2>] dpm_sysfs_remove+0x22/0x60
  40    [<ffffffff813f9db9>] device_del+0x49/0x240
  41    [<ffffffff815da768>] rfkill_unregister+0x58/0xc0
  42    [<ffffffffa06bd91b>] wiphy_unregister+0xab/0x2f0 [cfg80211]
  43    [<ffffffffa0742fe3>] brcmf_cfg80211_detach+0x23/0x50 [brcmfmac]
  44    [<ffffffffa074d986>] brcmf_detach+0x86/0xe0 [brcmfmac]
  45    [<ffffffffa0757de8>] brcmf_sdio_remove+0x48/0x120 [brcmfmac]
  46    [<ffffffffa0758ed9>] brcmf_sdiod_remove+0x29/0xd0 [brcmfmac]
  47    [<ffffffffa0759031>] brcmf_ops_sdio_remove+0xb1/0x110 [brcmfmac]
  48    [<ffffffffa001c267>] sdio_bus_remove+0x37/0x100 [mmc_core]
  49    [<ffffffff813fe026>] __device_release_driver+0x96/0x130
  50    [<ffffffff813fe0e3>] device_release_driver+0x23/0x30
  51    [<ffffffffa0754bc8>] brcmf_sdio_firmware_callback+0x2a8/0x5d0 [brcmfmac]
  52    [<ffffffffa074deaf>] brcmf_fw_request_nvram_done+0x15f/0x5e0 [brcmfmac]
  53    [<ffffffff8140142f>] ? devres_add+0x3f/0x50
  54    [<ffffffff810642b5>] ? usermodehelper_read_unlock+0x15/0x20
  55    [<ffffffff81400000>] ? platform_match+0x70/0xa0
  56    [<ffffffff8140f400>] request_firmware_work_func+0x30/0x60
  57    [<ffffffff8106828c>] process_one_work+0x14c/0x3d0
  58    [<ffffffff8106862a>] worker_thread+0x11a/0x450
  59    [<ffffffff81068510>] ? process_one_work+0x3d0/0x3d0
  60    [<ffffffff8106d692>] kthread+0xd2/0xf0
  61    [<ffffffff8106d5c0>] ? kthread_create_on_node+0x180/0x180
  62    [<ffffffff815ed35f>] ret_from_fork+0x3f/0x70
  63    [<ffffffff8106d5c0>] ? kthread_create_on_node+0x180/0x180
  64   Code: e9 40 fe ff ff 48 89 d8 eb 87 66 0f 1f 84 00 00 00 00 00 66 66 66 66
  65         90 55 48 89 e5 41 56 49 89 f6 41 55 49 89 d5 31 d2 41 54 53 <0f> b7
  66         47 68 48 8b 5f 48 66 c1 e8 05 83 e0 01 4d 85 ed 0f b6 c8
  67   RIP  [<ffffffff811e8f08>] kernfs_find_ns+0x18/0xd0
  68    RSP <ffff880036dd7a28>
  69   CR2: 0000000000000068
  70   ---[ end trace 87d6ec0d3fe46740 ]---
  71
  72 Reported-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
  73 Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
  74 Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
  75 Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
  76 Signed-off-by: Arend van Spriel <arend@broadcom.com>
  77 ---
  78
  79 --- a/drivers/net/wireless/brcm80211/brcmfmac/core.c
  80 +++ b/drivers/net/wireless/brcm80211/brcmfmac/core.c
  81 @@ -1049,7 +1049,10 @@ int brcmf_bus_start(struct device *dev)
  82  fail:
  83         if (ret < 0) {
  84                 brcmf_err("failed: %d\n", ret);
  85 -               brcmf_cfg80211_detach(drvr->config);
  86 +               if (drvr->config) {
  87 +                       brcmf_cfg80211_detach(drvr->config);
  88 +                       drvr->config = NULL;
  89 +               }
  90                 if (drvr->fws) {
  91                         brcmf_fws_del_interface(ifp);
  92                         brcmf_fws_deinit(drvr);