From: Johannes Berg Date: Fri, 11 Oct 2013 13:47:06 +0000 (+0200) Subject: mac80211: fix crash if bitrate calculation goes wrong X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=0b1621f62382e9b6f97b35861e9ade1a979b95b8;p=linux-edison.git mac80211: fix crash if bitrate calculation goes wrong commit d86aa4f8ca58898ec6a94c0635da20b948171ed7 upstream. If a frame's timestamp is calculated, and the bitrate calculation goes wrong and returns zero, the system will attempt to divide by zero and crash. Catch this case and print the rate information that the driver reported when this happens. Reported-by: Thomas Lindroth Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 72e6292955b..5db8eb5d56c 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -2174,6 +2174,10 @@ u64 ieee80211_calculate_rx_timestamp(struct ieee80211_local *local, } rate = cfg80211_calculate_bitrate(&ri); + if (WARN_ONCE(!rate, + "Invalid bitrate: flags=0x%x, idx=%d, vht_nss=%d\n", + status->flag, status->rate_idx, status->vht_nss)) + return 0; /* rewind from end of MPDU */ if (status->flag & RX_FLAG_MACTIME_END)