wifi: cfg80211: fix CQM for non-range use
authorJohannes Berg <johannes.berg@intel.com>
Sat, 16 Dec 2023 05:47:15 +0000 (05:47 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 5 Jan 2024 14:19:44 +0000 (15:19 +0100)
commitd673099085ddf1c28a6c0c1a245480919b5fe9e5
tree70373688031f904956c0ae36e6d2b410b1ac8c63
parentccd48707d51170a7518b77074f4053815ec58186
wifi: cfg80211: fix CQM for non-range use

commit 7e7efdda6adb385fbdfd6f819d76bc68c923c394 upstream.

[note: this is commit 4a7e92551618f3737b305f62451353ee05662f57 reapplied;
that commit had been reverted in 6.6.6 because it caused regressions, see
https://lore.kernel.org/stable/2023121450-habitual-transpose-68a1@gregkh/
for details]

My prior race fix here broke CQM when ranges aren't used, as
the reporting worker now requires the cqm_config to be set in
the wdev, but isn't set when there's no range configured.

Rather than continuing to special-case the range version, set
the cqm_config always and configure accordingly, also tracking
if range was used or not to be able to clear the configuration
appropriately with the same API, which was actually not right
if both were implemented by a driver for some reason, as is
the case with mac80211 (though there the implementations are
equivalent so it doesn't matter.)

Also, the original multiple-RSSI commit lost checking for the
callback, so might have potentially crashed if a driver had
neither implementation, and userspace tried to use it despite
not being advertised as supported.

Cc: stable@vger.kernel.org
Fixes: 4a4b8169501b ("cfg80211: Accept multiple RSSI thresholds for CQM")
Fixes: 37c20b2effe9 ("wifi: cfg80211: fix cqm_config access race")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Léo Lam" <leo@leolam.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/wireless/core.h
net/wireless/nl80211.c