On Mon, 2015-05-25 at 12:15 -0400, Bob Copeland wrote: > On Thu, May 21, 2015 at 06:05:13PM -0700, Alexis Green wrote: > > This patch fixes a NULL dereference in ath9k (and likely other drivers) when > > fixed mesh paths are used. The problem is that when a station comes up > > sta_info_alloc allocates ath_node implicitly via hw->sta_data_size. When it > > does that the ath_node is zeroed out. The ath_node isn’t actually initialized > > until the station becomes associated and ath9k_sta_state is called. > > Good catch. > > I wonder if we should instead remove the mesh special case in > ieee80211_tx_h_check_assoc() -- given that we require an assoc station in > peering before we send data frames to that RA, and userspace should also be > setting assoc flag after MPM completes, I can't think of a reason offhand why > we'd need to bail out there. > > Does this also fix the problem for you? It passed the wpa_supplicant test > cases at least (but we aren't fixing mpaths in any of those...) > > From 246febaa51d555fda437cc8064798db06c5f4d6e Mon Sep 17 00:00:00 2001 > From: Bob Copeland <me@xxxxxxxxxxxxxxx> > Date: Mon, 25 May 2015 12:01:52 -0400 > Subject: [PATCH] mac80211: enable assoc check for mesh interfaces > > We already set a station to be associated when peering completes, > both in user space and in the kernel. Thus we should always have > an associated sta before sending data frames to that station. > > Failure to do this can cause crashes in the lower-level driver due > to transmitting unicast data frames before driver sta structures > (e.g. ampdu state in ath9k) are initialized. This could have > happened if fixing mpaths, which could then allow TX to stations > with whom we haven't yet completed peering. > > Reported-by: Alexis Green <agreen@xxxxxxxxxxxx> > Signed-off-by: Bob Copeland <me@xxxxxxxxxxxxxxx> This looks reasonable to me - Alexis? johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
