[008/105] ath9k: Fix kernel panic in AR2427

Greg KH
2011-04-12T14:37:37Z

From: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>

commit 61e1b0b00c793ad5a32fe2181c9f77115fed5dc4 upstream.

Kernel panic occurs just after AR2427 establishes connection with AP.
Unless aggregation is enabled we don't initialize the TID structure.
Thus accesing the elements of the TID structure when aggregation is
disabled, leads to NULL pointer dereferencing.

[ 191.320358] Call Trace:
[ 191.320364] [<fd250ea7>] ? ath9k_tx+0xa7/0x200 [ath9k]
[ 191.320376] [<fd1ec7fc>] ? __ieee80211_tx+0x5c/0x1e0 [mac80211]
[ 191.320386] [<fd1edd2b>] ? ieee80211_tx+0x7b/0x90 [mac80211]
[ 191.320395] [<fd1edddd>] ? ieee80211_xmit+0x9d/0x1d0 [mac80211]
[ 191.320401] [<c014218f>] ? wake_up_state+0xf/0x20
[ 191.320405] [<c015dbc8>] ? signal_wake_up+0x28/0x40
[ 191.320410] [<c012a578>] ? default_spin_lock_flags+0x8/0x10
[ 191.320420] [<fd1ee308>] ? ieee80211_subif_start_xmit+0x2e8/0x7c0
[mac80211]
[ 191.320425] [<c058f905>] ? do_page_fault+0x295/0x3a0
[ 191.320431] [<c04c4a3d>] ? dev_hard_start_xmit+0x1ad/0x210
[ 191.320436] [<c04d96b5>] ? sch_direct_xmit+0x105/0x170
[ 191.320445] [<fd1f161a>] ? get_sta_flags+0x2a/0x40 [mac80211]
[ 191.320449] [<c04c780f>] ? dev_queue_xmit+0x37f/0x4b0
[ 191.320452] [<c04d75b0>] ? eth_header+0x0/0xb0
[ 191.320456] [<c04cc479>] ? neigh_resolve_output+0xe9/0x310
[ 191.320461] [<c053d295>] ? ip6_output_finish+0xa5/0x110
[ 191.320464] [<c053e354>] ? ip6_output2+0x134/0x250
[ 191.320468] [<c053f7dd>] ? ip6_output+0x6d/0x100
[ 191.320471] [<c0559665>] ? mld_sendpack+0x395/0x3e0
[ 191.320475] [<c0557f81>] ? add_grhead+0x31/0xa0
[ 191.320478] [<c055a83c>] ? mld_send_cr+0x1bc/0x2b0
[ 191.320482] [<c01535d9>] ? irq_exit+0x39/0x70
[ 191.320485] [<c055a940>] ? mld_ifc_timer_expire+0x10/0x40
[ 191.320489] [<c015b92e>] ? run_timer_softirq+0x13e/0x2c0
[ 191.320493] [<c0103a30>] ? common_interrupt+0x30/0x40
[ 191.320498] [<c055a930>] ? mld_ifc_timer_expire+0x0/0x40
[ 191.320502] [<c0153358>] ? __do_softirq+0x98/0x1b0
[ 191.320506] [<c01534b5>] ? do_softirq+0x45/0x50
[ 191.320509] [<c0153605>] ? irq_exit+0x65/0x70
[ 191.320513] [<c05917dc>] ? smp_apic_timer_interrupt+0x5c/0x8b
[ 191.320516] [<c0103df1>] ? apic_timer_interrupt+0x31/0x40
[ 191.320521] [<c016007b>] ? k_getrusage+0x12b/0x2f0
[ 191.320525] [<c039e384>] ? acpi_idle_enter_simple+0x117/0x148
[ 191.320529] [<c04a20da>] ? cpuidle_idle_call+0x7a/0x100
[ 191.320532] [<c01021d4>] ? cpu_idle+0x94/0xd0
[ 191.320536] [<c057ab88>] ? rest_init+0x58/0x60
[ 191.320541] [<c07a58ec>] ? start_kernel+0x351/0x357
[ 191.320544] [<c07a53c7>] ? unknown_bootoption+0x0/0x19e
[ 191.320548] [<c07a50aa>] ? i386_start_kernel+0xaa/0xb1
[ 191.320550] Code: 03 66 3d 00 03 0f 84 7c 02 00 00 83 c3 18 0f b6 03
8b 4d e0 89 c3 83 e3 0f 6b c3 48 89 5d d8 8d 04 06 8d 50 0c 89 55 d0 8b
40 20 <8b> 00 3b 01 0f 85 8e 02 00 00 f6 47 20 40 0f 84 29 ff ff ff 8b
[ 191.320634] EIP: [<fd2586d4>] ath_tx_start+0x474/0x770 [ath9k] SS:ESP
0068:c0761a90
[ 191.320642] CR2: 0000000000000000
[ 191.320647] ---[ end trace 9296ef23b9076ece ]---
[ 191.320650] Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/wireless/ath/ath9k/xmit.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1699,8 +1699,8 @@ static void ath_tx_start_dma(struct ath_
u8 tidno;

spin_lock_bh(&txctl->txq->axq_lock);
-
- if (ieee80211_is_data_qos(hdr->frame_control) && txctl->an) {
+ if ((sc->sc_flags & SC_OP_TXAGGR) && txctl->an &&
+ ieee80211_is_data_qos(hdr->frame_control)) {
tidno = ieee80211_get_qos_ctl(hdr)[0] &
IEEE80211_QOS_CTL_TID_MASK;
tid = ATH_AN_2_TID(txctl->an, tidno);