From d86aa4f8ca58898ec6a94c0635da20b948171ed7 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 11 Oct 2013 15:47:06 +0200 Subject: [PATCH] mac80211: fix crash if bitrate calculation goes wrong 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. Cc: stable@vger.kernel.org Reported-by: Thomas Lindroth Signed-off-by: Johannes Berg --- net/mac80211/util.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 9c3200bcfc02..69e4ef5348a0 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -2238,6 +2238,10 @@ 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)