git.openwrt.org Git - openwrt/openwrt.git/blob

   1 From 552ba102a6898630a7d16887f29e606d6fabe508 Mon Sep 17 00:00:00 2001
   2 From: Siddh Raman Pant <code@siddh.me>
   3 Date: Sun, 14 Aug 2022 20:45:12 +0530
   4 Subject: [PATCH] wifi: mac80211: Don't finalize CSA in IBSS mode if state is
   5  disconnected
   6
   7 commit 15bc8966b6d3a5b9bfe4c9facfa02f2b69b1e5f0 upstream.
   8
   9 When we are not connected to a channel, sending channel "switch"
  10 announcement doesn't make any sense.
  11
  12 The BSS list is empty in that case. This causes the for loop in
  13 cfg80211_get_bss() to be bypassed, so the function returns NULL
  14 (check line 1424 of net/wireless/scan.c), causing the WARN_ON()
  15 in ieee80211_ibss_csa_beacon() to get triggered (check line 500
  16 of net/mac80211/ibss.c), which was consequently reported on the
  17 syzkaller dashboard.
  18
  19 Thus, check if we have an existing connection before generating
  20 the CSA beacon in ieee80211_ibss_finish_csa().
  21
  22 Cc: stable@vger.kernel.org
  23 Fixes: cd7760e62c2a ("mac80211: add support for CSA in IBSS mode")
  24 Link: https://syzkaller.appspot.com/bug?id=05603ef4ae8926761b678d2939a3b2ad28ab9ca6
  25 Reported-by: syzbot+b6c9fe29aefe68e4ad34@syzkaller.appspotmail.com
  26 Signed-off-by: Siddh Raman Pant <code@siddh.me>
  27 Tested-by: syzbot+b6c9fe29aefe68e4ad34@syzkaller.appspotmail.com
  28 Link: https://lore.kernel.org/r/20220814151512.9985-1-code@siddh.me
  29 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  30 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  31 ---
  32  net/mac80211/ibss.c | 4 ++++
  33  1 file changed, 4 insertions(+)
  34
  35 --- a/net/mac80211/ibss.c
  36 +++ b/net/mac80211/ibss.c
  37 @@ -534,6 +534,10 @@ int ieee80211_ibss_finish_csa(struct iee
  38
  39         sdata_assert_lock(sdata);
  40
  41 +       /* When not connected/joined, sending CSA doesn't make sense. */
  42 +       if (ifibss->state != IEEE80211_IBSS_MLME_JOINED)
  43 +               return -ENOLINK;
  44 +
  45         /* update cfg80211 bss information with the new channel */
  46         if (!is_zero_ether_addr(ifibss->bssid)) {
  47                 cbss = cfg80211_get_bss(sdata->local->hw.wiphy,