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authorLuis R. Rodriguez <lrodriguez@atheros.com>2009-08-11 13:10:33 -0700
committerJohn W. Linville <linville@tuxdriver.com>2009-08-13 14:47:42 -0400
commit416fbdff2137e8d8cc8f23f517bee3a26b11526f (patch)
tree83ad1a5397c100fc9d08fd239b5e1b105b96028b
parent839d1624b9dcf31fdc02e47359043bb7bd71d6ca (diff)
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mac80211: fix panic when splicing unprepared TIDs
We splice skbs from the pending queue for a TID onto the local pending queue when tearing down a block ack request. This is not necessary unless we actually have received a request to start a block ack request (rate control, for example). If we never received that request we should not be splicing the tid pending queue as it would be null, causing a panic. Not sure yet how exactly we allowed through a call when the tid state does not have at least HT_ADDBA_REQUESTED_MSK set, that will require some further review as it is not quite obvious. For more information see the bug report: http://bugzilla.kernel.org/show_bug.cgi?id=13922 This fixes this oops: BUG: unable to handle kernel NULL pointer dereference at 00000030 IP: [<f8806c70>] ieee80211_agg_splice_packets+0x40/0xc0 [mac80211] *pdpt = 0000000002d1e001 *pde = 0000000000000000 Thread overran stack, or stack corrupted Oops: 0000 [#1] SMP last sysfs file: /sys/module/aes_generic/initstate Modules linked in: <bleh> Pid: 0, comm: swapper Not tainted (2.6.31-rc5-wl #2) Dell DV051 EIP: 0060:[<f8806c70>] EFLAGS: 00010292 CPU: 0 EIP is at ieee80211_agg_splice_packets+0x40/0xc0 [mac80211] EAX: 00000030 EBX: 0000004c ECX: 00000003 EDX: 00000000 ESI: c1c98000 EDI: f745a1c0 EBP: c076be58 ESP: c076be38 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 Process swapper (pid: 0, ti=c076a000 task=c0709160 task.ti=c076a000) Stack: <bleh2> Call Trace: [<f8806edb>] ? ieee80211_stop_tx_ba_cb+0xab/0x150 [mac80211] [<f8802f1e>] ? ieee80211_tasklet_handler+0xce/0x110 [mac80211] [<c04862ff>] ? net_rx_action+0xef/0x1d0 [<c0149378>] ? tasklet_action+0x58/0xc0 [<c014a0f2>] ? __do_softirq+0xc2/0x190 [<c018eb48>] ? handle_IRQ_event+0x58/0x140 [<c01205fe>] ? ack_apic_level+0x7e/0x270 [<c014a1fd>] ? do_softirq+0x3d/0x40 [<c014a345>] ? irq_exit+0x65/0x90 [<c010a6af>] ? do_IRQ+0x4f/0xc0 [<c014a35d>] ? irq_exit+0x7d/0x90 [<c011d547>] ? smp_apic_timer_interrupt+0x57/0x90 [<c01094a9>] ? common_interrupt+0x29/0x30 [<c010fd9e>] ? mwait_idle+0xbe/0x100 [<c0107e42>] ? cpu_idle+0x52/0x90 [<c054b1a5>] ? rest_init+0x55/0x60 [<c077492d>] ? start_kernel+0x315/0x37d [<c07743ce>] ? unknown_bootoption+0x0/0x1f9 [<c0774099>] ? i386_start_kernel+0x79/0x81 Code: <bleh3> EIP: [<f8806c70>] ieee80211_agg_splice_packets+0x40/0xc0 [mac80211] SS:ESP 0068:c076be38 CR2: 0000000000000030 Cc: stable@kernel.org Testedy-by: Jack Lau <jackelectronics@hotmail.com> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--net/mac80211/agg-tx.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 9e5762ad307d..a24e59816b93 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -381,6 +381,14 @@ static void ieee80211_agg_splice_packets(struct ieee80211_local *local,
&local->hw, queue,
IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
+ if (!(sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK))
+ return;
+
+ if (WARN(!sta->ampdu_mlme.tid_tx[tid],
+ "TID %d gone but expected when splicing aggregates from"
+ "the pending queue\n", tid))
+ return;
+
if (!skb_queue_empty(&sta->ampdu_mlme.tid_tx[tid]->pending)) {
spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
/* mark queue as pending, it is stopped already */