commit: 674db1344443204b6ce3293f2df8fd1b7665deea
From: Stanislaw Gruszka <sgrus...@redhat.com>
Date: Wed, 10 Aug 2011 15:32:24 +0200
Subject: [PATCH] rt2x00: fix crash in rt2800usb_get_txwi
Patch should fix this oops:
BUG: unable to handle kernel NULL pointer dereference at 000000a0
IP: [<f81b30c9>] rt2800usb_get_txwi+0x19/0x70 [rt2800usb]
*pdpt = 0000000000000000 *pde = f000ff53f000ff53
Oops: 0000 [#1] SMP
Pid: 198, comm: kworker/u:3 Tainted: G W 3.0.0-wl+ #9 LENOVO
6369CTO/6369CTO
EIP: 0060:[<f81b30c9>] EFLAGS: 00010283 CPU: 1
EIP is at rt2800usb_get_txwi+0x19/0x70 [rt2800usb]
EAX: 00000000 EBX: f465e140 ECX: f4494960 EDX: ef24c5f8
ESI: 810f21f5 EDI: f1da9960 EBP: f4581e80 ESP: f4581e70
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process kworker/u:3 (pid: 198, ti=f4580000 task=f4494960 task.ti=f4580000)
Call Trace:
[<f804790f>] rt2800_txdone_entry+0x2f/0xf0 [rt2800lib]
[<c045110d>] ? warn_slowpath_common+0x7d/0xa0
[<f81b3a38>] ? rt2800usb_work_txdone+0x288/0x360 [rt2800usb]
[<f81b3a38>] ? rt2800usb_work_txdone+0x288/0x360 [rt2800usb]
[<f81b3a13>] rt2800usb_work_txdone+0x263/0x360 [rt2800usb]
[<c046a8d6>] process_one_work+0x186/0x440
[<c046a85a>] ? process_one_work+0x10a/0x440
[<f81b37b0>] ? rt2800usb_probe_hw+0x120/0x120 [rt2800usb]
[<c046c283>] worker_thread+0x133/0x310
[<c04885db>] ? trace_hardirqs_on+0xb/0x10
[<c046c150>] ? manage_workers+0x1e0/0x1e0
[<c047054c>] kthread+0x7c/0x90
[<c04704d0>] ? __init_kthread_worker+0x60/0x60
[<c0826b42>] kernel_thread_helper+0x6/0x1
Oops might happen because we check rt2x00queue_empty(queue) twice,
but this condition can change and we can process entry in
rt2800_txdone_entry(), which was already processed by
rt2800usb_txdone_entry_check() -> rt2x00lib_txdone_noinfo() and
has nullify entry->skb .
Reported-by: Justin Piszcz <jpis...@lucidpixels.com>
Cc: sta...@kernel.org
Signed-off-by: Stanislaw Gruszka <sgrus...@redhat.com>
Acked-by: Ivo van Doorn <ivdo...@gmail.com>
Signed-off-by: John W. Linville <linvi...@tuxdriver.com>
---
drivers/net/wireless/rt2x00/rt2800usb.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c
b/drivers/net/wireless/rt2x00/rt2800usb.c
index 2cb25ea..dbf501c 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -538,12 +538,11 @@ static void rt2800usb_txdone(struct rt2x00_dev *rt2x00dev)
entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
if (rt2800usb_txdone_entry_check(entry, reg))
break;
+ entry = NULL;
}
- if (!entry || rt2x00queue_empty(queue))
- break;
-
- rt2800_txdone_entry(entry, reg);
+ if (entry)
+ rt2800_txdone_entry(entry, reg);
}
}
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