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