From 19b9675069cb06ae17d1595ac517d475d75e6bb9 Mon Sep 17 00:00:00 2001 From: Senthil Balasubramanian Date: Wed, 23 Mar 2011 23:07:21 +0530 Subject: [PATCH] ath9k: Fix kernel panic caused by invalid rate index access. With the recent tx status optimization in mac80211, we bail out as and and when invalid rate index is found. So the behavior of resetting rate idx to -1 and count to 0 has changed for the rate indexes that were not part of the driver's retry series. This has resulted in ath9k using incorrect rate table index which caused the system to panic. Ideally ath9k need to loop only for the indexes that were part of the retry series and so simply use hw->max_rates as the loop counter. Pasted the stack trace of the panic issue for reference. [ 754.093192] BUG: unable to handle kernel paging request at ffff88046a9025b0 [ 754.093256] IP: [] ath_tx_status+0x209/0x2f0 [ath9k] [ 754.094888] Call Trace: [ 754.094903] [ 754.094928] [] ieee80211_tx_status+0x203/0x9e0 [mac80211] [ 754.094975] [] ? __ieee80211_wake_queue+0x125/0x140 [mac80211] [ 754.095017] [] ath_tx_complete_buf+0x1b9/0x370 [ath9k] [ 754.095054] [] ath_tx_complete_aggr+0x51f/0xb50 [ath9k] [ 754.095098] [] ? ieee80211_prepare_and_rx_handle+0x173/0xab0 [mac80211] [ 754.095148] [] ? _raw_spin_unlock_irqrestore+0x32/0x40 [ 754.095186] [] ath_tx_tasklet+0x365/0x4b0 [ath9k] [ 754.095224] [] ? clockevents_program_event+0x62/0xa0 [ 754.095261] [] ath9k_tasklet+0x168/0x1c0 [ath9k] [ 754.095298] [] tasklet_action+0x6b/0xe0 [ 754.095331] [] __do_softirq+0x98/0x120 [ 754.095361] [] call_softirq+0x1c/0x30 [ 754.095393] [] do_softirq+0x65/0xa0 [ 754.095423] [] irq_exit+0x8d/0x90 [ 754.095453] [] do_IRQ+0x61/0xe0 [ 754.095482] [] ret_from_intr+0x0/0x15 [ 754.095513] [ 754.095531] [] ? native_sched_clock+0x15/0x70 [ 754.096475] [] ? acpi_idle_enter_bm+0x24d/0x285 [processor] [ 754.096475] [] ? acpi_idle_enter_bm+0x246/0x285 [processor] [ 754.096475] [] cpuidle_idle_call+0x82/0x100 [ 754.096475] [] cpu_idle+0xa6/0xf0 [ 754.096475] [] rest_init+0x91/0xa0 [ 754.096475] [] start_kernel+0x3fd/0x408 [ 754.096475] [] x86_64_start_reservations+0x132/0x136 [ 754.096475] [] x86_64_start_kernel+0x106/0x115 [ 754.096475] RIP [] ath_tx_status+0x209/0x2f0 [ath9k] Signed-off-by: Senthil Balasubramanian Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath9k/rc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c index 960d717ca7c2..a3241cd089b1 100644 --- a/drivers/net/wireless/ath/ath9k/rc.c +++ b/drivers/net/wireless/ath/ath9k/rc.c @@ -1328,7 +1328,7 @@ static void ath_tx_status(void *priv, struct ieee80211_supported_band *sband, hdr = (struct ieee80211_hdr *)skb->data; fc = hdr->frame_control; - for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { + for (i = 0; i < sc->hw->max_rates; i++) { struct ieee80211_tx_rate *rate = &tx_info->status.rates[i]; if (!rate->count) break; -- 2.20.1