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authorTom Hughes <tom@compton.nu>2012-06-27 18:21:15 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-07-16 09:04:41 -0700
commite5982925c66c542aa41b17ee35fc233ae1521898 (patch)
tree1f761b55d38af49cf028b1b0944a399b828850f2 /drivers
parent5250def1935443f4bbddce101281e0aaf2e66838 (diff)
ath9k: fix panic caused by returning a descriptor we have queued for reuse
commit 6bb51c70cabaadddc54a6454844eceba91a56083 upstream. Commit 3a2923e83c introduced a bug when a corrupt descriptor is encountered - although the following descriptor is discarded and returned to the queue for reuse the associated frame is also returned for processing. This leads to a panic: BUG: unable to handle kernel NULL pointer dereference at 000000000000003a IP: [<ffffffffa02599a5>] ath_rx_tasklet+0x165/0x1b00 [ath9k] Call Trace: <IRQ> [<ffffffff812d7fa0>] ? map_single+0x60/0x60 [<ffffffffa028f044>] ? ath9k_ioread32+0x34/0x90 [ath9k] [<ffffffffa0292eec>] athk9k_tasklet+0xdc/0x160 [ath9k] [<ffffffff8105e133>] tasklet_action+0x63/0xd0 [<ffffffff8105dbc0>] __do_softirq+0xc0/0x1e0 [<ffffffff8101a873>] ? native_sched_clock+0x13/0x80 [<ffffffff815f9d5c>] call_softirq+0x1c/0x30 [<ffffffff810151f5>] do_softirq+0x75/0xb0 [<ffffffff8105df95>] irq_exit+0xb5/0xc0 [<ffffffff815fa5b3>] do_IRQ+0x63/0xe0 [<ffffffff815f0cea>] common_interrupt+0x6a/0x6a <EOI> [<ffffffff8131840a>] ? intel_idle+0xea/0x150 [<ffffffff813183eb>] ? intel_idle+0xcb/0x150 [<ffffffff814a1db9>] cpuidle_enter+0x19/0x20 [<ffffffff814a23d9>] cpuidle_idle_call+0xa9/0x240 [<ffffffff8101c4bf>] cpu_idle+0xaf/0x120 [<ffffffff815cda8e>] rest_init+0x72/0x74 [<ffffffff81cf4c1a>] start_kernel+0x3b7/0x3c4 [<ffffffff81cf4662>] ? repair_env_string+0x5e/0x5e [<ffffffff81cf4346>] x86_64_start_reservations+0x131/0x135 [<ffffffff81cf444a>] x86_64_start_kernel+0x100/0x10f Making sure bf is cleared to NULL in this case restores the old behaviour. Signed-off-by: Tom Hughes <tom@compton.nu> Signed-off-by: John W. Linville <linville@tuxdriver.com> Cc: Josh Boyer <jwboyer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/wireless/ath/ath9k/recv.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 1efd6c9beb34..a2f7ae81a414 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -695,9 +695,9 @@ static bool ath_edma_get_buffers(struct ath_softc *sc,
__skb_unlink(skb, &rx_edma->rx_fifo);
list_add_tail(&bf->list, &sc->rx.rxbuf);
ath_rx_edma_buf_link(sc, qtype);
- } else {
- bf = NULL;
}
+
+ bf = NULL;
}
*dest = bf;