Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   James Prestwood <prestwoj@gmail.com>
To:     linux-wireless@vger.kernel.org
Cc:     James Prestwood <prestwoj@gmail.com>
Subject: [PATCH 0/1] Fix potential HE IE bug and some other questions
Date:   Wed, 28 Sep 2022 15:49:09 -0700
Message-Id: <20220928224910.453232-1-prestwoj@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

I believe there is a bug when building the probe request IEs for the
HE capabilities. More info in the patch. While looking at this I
noticed some other confusing code related to building the probe
request.

Looking at ieee80211_build_preq_ies. It is passed 'bands_used' which
is a bitmask of bands. A probe request is only sent out on a single
band so why would this contain multiple bands? We then loop over these
bands and call ieee80211_build_preq_ies_band for each one.
This, AFAICT, would append the same IEs multiple times if 'bands_used'
contained more than one band. Internal to mac80211/util.c its only
passed BIT(chan->band), but mac80211/scan.c seems to pass a list...

Below is the warning I am seeing (many, many times). It says the warning
is in build_preq_ies, but it really seems like this is not correct
and its actually in ieee80211_get_he_6ghz_capa since I see no warning
message as others _should_ have.

[  732.130000] ------------[ cut here ]------------
[  732.130000] WARNING: CPU: 0 PID: 1352 at include/net/cfg80211.h:608 ieee80211_build_preq_ies+0x766/0x84d
[  732.130000] Modules linked in:
[  732.130000] CPU: 0 PID: 1352 Comm: kworker/u2:0 Tainted: G        W         5.19.0 #1
[  732.130000] Workqueue: rad6 ieee80211_scan_work
[  732.130000] Stack:
[  732.130000]  605d0943 60256c96 60035421 00000001
[  732.130000]  6052cddd 60450efa 61f3d5d9 60454c00
[  732.130000]  00000000 00000000 00000009 6003e77d
[  732.130000] Call Trace:
[  732.130000]  [<60256c96>] ? dump_stack_print_info+0xe1/0xef
[  732.130000]  [<60035421>] ? um_set_signals+0x0/0x3c
[  732.130000]  [<60450efa>] ? _printk+0x0/0x9f
[  732.130000]  [<60454c00>] ? dump_stack_lvl+0x47/0x52
[  732.130000]  [<6003e77d>] ? __warn+0xf2/0x123
[  732.130000]  [<60035449>] ? um_set_signals+0x28/0x3c
[  732.130000]  [<604501bb>] ? warn_slowpath_fmt+0xd6/0xe2
[  732.130000]  [<6042830f>] ? ieee80211_prepare_and_rx_handle+0xbf4/0xc22
[  732.130000]  [<604500e5>] ? warn_slowpath_fmt+0x0/0xe2
[  732.130000]  [<603d3bc5>] ? ieee80211_ie_split_ric+0xe4/0xfe
[  732.130000]  [<60035421>] ? um_set_signals+0x0/0x3c
[  732.130000]  [<604341ac>] ? ieee80211_vif_type_p2p+0x0/0x26
[  732.130000]  [<6043aeb5>] ? ieee80211_build_preq_ies+0x766/0x84d
[  732.130000]  [<60035377>] ? unblock_signals+0x36/0xe0
[  732.130000]  [<60429f6c>] ? skb_put_zero+0x2c/0x34
[  732.130000]  [<60429f40>] ? skb_put_zero+0x0/0x34
[  732.130000]  [<6043b095>] ? ieee80211_build_probe_req+0xf9/0x161
[  732.130000]  [<6040c2ed>] ? ieee80211_scan_state_send_probe+0xaf/0x14c
[  732.130000]  [<60051181>] ? queue_delayed_work_on+0x67/0x72
[  732.130000]  [<6040d1b0>] ? ieee80211_scan_work+0x40b/0x503
[  732.130000]  [<6040cda5>] ? ieee80211_scan_work+0x0/0x503
[  732.130000]  [<600529de>] ? process_one_work+0x1b0/0x2b1
[  732.130000]  [<6004f829>] ? move_linked_works+0x0/0x57
[  732.130000]  [<60053086>] ? worker_thread+0x270/0x39b
[  732.130000]  [<6004f909>] ? set_pf_worker+0x0/0x5f
[  732.130000]  [<60057231>] ? arch_local_irq_save+0x0/0x26
[  732.130000]  [<60035449>] ? um_set_signals+0x28/0x3c
[  732.130000]  [<60052e16>] ? worker_thread+0x0/0x39b
[  732.130000]  [<600588ef>] ? kthread_exit+0x0/0x37
[  732.130000]  [<60052e16>] ? worker_thread+0x0/0x39b
[  732.130000]  [<60058a6d>] ? kthread+0x11f/0x124
[  732.130000]  [<60035377>] ? unblock_signals+0x36/0xe0
[  732.130000]  [<60021f95>] ? new_thread_handler+0x86/0xbb
[  732.130000] ---[ end trace 0000000000000000 ]---
[  732.210000] ------------[ cut here ]------------


James Prestwood (1):
  wifi: mac80211: fix probe req HE capabilities access

 net/mac80211/util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.34.3