wifi: cfg80211: fix BSS refcounting bugs
There are multiple refcounting bugs related to multi-BSSID:
- In bss_ref_get(), if the BSS has a hidden_beacon_bss, then
the bss pointer is overwritten before checking for the
transmitted BSS, which is clearly wrong. Fix this by using
the bss_from_pub() macro.
- In cfg80211_bss_update() we copy the transmitted_bss pointer
from tmp into new, but then if we release new, we'll unref
it erroneously. We already set the pointer and ref it, but
need to NULL it since it was copied from the tmp data.
- In cfg80211_inform_single_bss_data(), if adding to the non-
transmitted list fails, we unlink the BSS and yet still we
return it, but this results in returning an entry without
a reference. We shouldn't return it anyway if it was broken
enough to not get added there.
This fixes CVE-2022-42720.
Reported-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: a3584f56de1c ("cfg80211: Properly track transmitting and non-transmitting BSS")
Link: https://lore.kernel.org/lkml/20221013175147.168042993@linuxfoundation.org/
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Change-Id: If6ed330dc65fdf387ee8584b5a69840242edf5cc
Signed-off-by: Balaji Pothunoori <quic_bpothuno@quicinc.com>
1 file changed