USB: cdc-acm: fix memory corruption / panic

Prevent read urbs from being resubmitted from tasklet after port close.

The receive tasklet was not disabled on port close, which could lead to
corruption of receive lists on consecutive port open. In particular,
read urbs could be re-submitted before port open, added to free list in
open, and then added a second time to the free list in the completion
handler.

cdc-acm.c: Entering acm_tty_open.
cdc-acm.c: acm_control_msg: rq: 0x22 val: 0x3 len: 0x0 result: 0
cdc-acm.c: Entering acm_rx_tasklet
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da280, rcv 0xf57fbc24, buf 0xf57fbd64
cdc-acm.c: set line: 115200 0 0 8
cdc-acm.c: acm_control_msg: rq: 0x20 val: 0x0 len: 0x7 result: 7
cdc-acm.c: acm_tty_close
cdc-acm.c: acm_port_down
cdc-acm.c: acm_control_msg: rq: 0x22 val: 0x0 len: 0x0 result: 0
cdc-acm.c: acm_ctrl_irq - urb shutting down with status: -2
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da300, rcv 0xf57fbc10, buf 0xf57fbd50
cdc-acm.c: Entering acm_read_bulk with status -2
cdc_acm 4-1:1.1: Aborting, acm not ready
cdc-acm.c: Entering acm_read_bulk with status -2
cdc_acm 4-1:1.1: Aborting, acm not ready
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da380, rcv 0xf57fbbfc, buf 0xf57fbd3c
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da400, rcv 0xf57fbbe8, buf 0xf57fbd28
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da480, rcv 0xf57fbbd4, buf 0xf57fbd14
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da900, rcv 0xf57fbbc0, buf 0xf57fbd00
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da980, rcv 0xf57fbbac, buf 0xf57fbcec
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50daa00, rcv 0xf57fbb98, buf 0xf57fbcd8
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50daa80, rcv 0xf57fbb84, buf 0xf57fbcc4
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50dab00, rcv 0xf57fbb70, buf 0xf57fbcb0
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50dab80, rcv 0xf57fbb5c, buf 0xf57fbc9c
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50dac00, rcv 0xf57fbb48, buf 0xf57fbc88
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50dac80, rcv 0xf57fbb34, buf 0xf57fbc74
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50dad00, rcv 0xf57fbb20, buf 0xf57fbc60
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50dad80, rcv 0xf57fbb0c, buf 0xf57fbc4c
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da880, rcv 0xf57fbaf8, buf 0xf57fbc38
cdc-acm.c: Entering acm_tty_open.
cdc-acm.c: acm_control_msg: rq: 0x22 val: 0x3 len: 0x0 result: 0
cdc-acm.c: Entering acm_rx_tasklet
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da280, rcv 0xf57fbc24, buf 0xf57fbd64
cdc-acm.c: Entering acm_tty_write to write 3 bytes,
cdc-acm.c: Get 3 bytes...
cdc-acm.c: acm_write_start susp_count: 0
cdc-acm.c: Entering acm_read_bulk with status 0
------------[ cut here ]------------
WARNING: at /home/johan/src/linux/linux-2.6/lib/list_debug.c:57 list_del+0x10c/0x120()
Hardware name: Vostro 1520
list_del corruption. next->prev should be f57fbc10, but was f57fbaf8
Modules linked in: cdc_acm
Pid: 3, comm: ksoftirqd/0 Not tainted 2.6.37+ #39
Call Trace:
 [<c103c7e2>] warn_slowpath_common+0x72/0xa0
 [<c11dd8ac>] ? list_del+0x10c/0x120
 [<c11dd8ac>] ? list_del+0x10c/0x120
 [<c103c8b3>] warn_slowpath_fmt+0x33/0x40
 [<c11dd8ac>] list_del+0x10c/0x120
 [<f8051dbf>] acm_rx_tasklet+0xef/0x3e0 [cdc_acm]
 [<c135465d>] ? net_rps_action_and_irq_enable+0x6d/0x80
 [<c1042bb6>] tasklet_action+0xe6/0x140
 [<c104342f>] __do_softirq+0xaf/0x210
 [<c1043380>] ? __do_softirq+0x0/0x210
 <IRQ>  [<c1042c9a>] ? run_ksoftirqd+0x8a/0x1c0
 [<c1042c10>] ? run_ksoftirqd+0x0/0x1c0
 [<c105ac24>] ? kthread+0x74/0x80
 [<c105abb0>] ? kthread+0x0/0x80
 [<c100337a>] ? kernel_thread_helper+0x6/0x10
---[ end trace efd9a11434f0082e ]---
------------[ cut here ]------------
WARNING: at /home/johan/src/linux/linux-2.6/lib/list_debug.c:57 list_del+0x10c/0x120()
Hardware name: Vostro 1520
list_del corruption. next->prev should be f57fbd50, but was f57fbdb0
Modules linked in: cdc_acm
Pid: 3, comm: ksoftirqd/0 Tainted: G        W   2.6.37+ #39
Call Trace:
 [<c103c7e2>] warn_slowpath_common+0x72/0xa0
 [<c11dd8ac>] ? list_del+0x10c/0x120
 [<c11dd8ac>] ? list_del+0x10c/0x120
 [<c103c8b3>] warn_slowpath_fmt+0x33/0x40
 [<c11dd8ac>] list_del+0x10c/0x120
 [<f8051dd6>] acm_rx_tasklet+0x106/0x3e0 [cdc_acm]
 [<c135465d>] ? net_rps_action_and_irq_enable+0x6d/0x80
 [<c1042bb6>] tasklet_action+0xe6/0x140
 [<c104342f>] __do_softirq+0xaf/0x210
 [<c1043380>] ? __do_softirq+0x0/0x210
 <IRQ>  [<c1042c9a>] ? run_ksoftirqd+0x8a/0x1c0
 [<c1042c10>] ? run_ksoftirqd+0x0/0x1c0
 [<c105ac24>] ? kthread+0x74/0x80
 [<c105abb0>] ? kthread+0x0/0x80
 [<c100337a>] ? kernel_thread_helper+0x6/0x10
---[ end trace efd9a11434f0082f ]---
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da300, rcv 0xf57fbc10, buf 0xf57fbd50
cdc-acm.c: disconnected from network
cdc-acm.c: acm_rx_tasklet: sending urb 0xf50da380, rcv 0xf57fbbfc, buf 0xf57fbd3c
cdc-acm.c: Entering acm_rx_tasklet
------------[ cut here ]------------
WARNING: at /home/johan/src/linux/linux-2.6/lib/list_debug.c:48 list_del+0xd5/0x120()
Hardware name: Vostro 1520
list_del corruption, next is LIST_POISON1 (00100100)
Modules linked in: cdc_acm
Pid: 3, comm: ksoftirqd/0 Tainted: G        W   2.6.37+ #39
Call Trace:
 [<c103c7e2>] warn_slowpath_common+0x72/0xa0
 [<c11dd875>] ? list_del+0xd5/0x120
 [<c11dd875>] ? list_del+0xd5/0x120
 [<c103c8b3>] warn_slowpath_fmt+0x33/0x40
 [<c11dd875>] list_del+0xd5/0x120
 [<f8051fac>] acm_rx_tasklet+0x2dc/0x3e0 [cdc_acm]
 [<c106dbab>] ? trace_hardirqs_on+0xb/0x10
 [<c1042b30>] ? tasklet_action+0x60/0x140
 [<c1042bb6>] tasklet_action+0xe6/0x140
 [<c104342f>] __do_softirq+0xaf/0x210
 [<c1043380>] ? __do_softirq+0x0/0x210
 <IRQ>  [<c1042c9a>] ? run_ksoftirqd+0x8a/0x1c0
 [<c1042c10>] ? run_ksoftirqd+0x0/0x1c0
 [<c105ac24>] ? kthread+0x74/0x80
 [<c105abb0>] ? kthread+0x0/0x80
 [<c100337a>] ? kernel_thread_helper+0x6/0x10
---[ end trace efd9a11434f00830 ]---
BUG: unable to handle kernel paging request at 00200200
IP: [<c11dd7bd>] list_del+0x1d/0x120
*pde = 00000000
Oops: 0000 [#1] PREEMPT SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:1a.1/usb4/4-1/4-1:1.0/tty/ttyACM0/uevent
Modules linked in: cdc_acm
Pid: 3, comm: ksoftirqd/0 Tainted: G        W   2.6.37+ #39 0T816J/Vostro 1520
EIP: 0060:[<c11dd7bd>] EFLAGS: 00010046 CPU: 0
EIP is at list_del+0x1d/0x120
EAX: f57fbd3c EBX: f57fb800 ECX: ffff8000 EDX: 00200200
ESI: f57fbe90 EDI: f57fbd3c EBP: f600bf54 ESP: f600bf3c
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process ksoftirqd/0 (pid: 3, ti=f600a000 task=f60791c0 task.ti=f6082000)
Stack:
 c1527e84 00000030 c1527e54 00100100 f57fb800 f57fbd3c f600bf98 f8051fac
 f8053104 f8052b94 f600bf6c c106dbab f600bf80 00000286 f60791c0 c1042b30
 f57fbda8 f57f5800 f57fbdb0 f57fbd80 f57fbe7c c1656b04 00000000 f600bfb0
Call Trace:
 [<f8051fac>] ? acm_rx_tasklet+0x2dc/0x3e0 [cdc_acm]
 [<c106dbab>] ? trace_hardirqs_on+0xb/0x10
 [<c1042b30>] ? tasklet_action+0x60/0x140
 [<c1042bb6>] ? tasklet_action+0xe6/0x140
 [<c104342f>] ? __do_softirq+0xaf/0x210
 [<c1043380>] ? __do_softirq+0x0/0x210
 <IRQ>
 [<c1042c9a>] ? run_ksoftirqd+0x8a/0x1c0
 [<c1042c10>] ? run_ksoftirqd+0x0/0x1c0
 [<c105ac24>] ? kthread+0x74/0x80
 [<c105abb0>] ? kthread+0x0/0x80
 [<c100337a>] ? kernel_thread_helper+0x6/0x10
Code: ff 48 14 e9 57 ff ff ff 90 90 90 90 90 90 55 89 e5 83 ec 18 81 38 00 01 10 00 0f 84 9c 00 00 00 8b 50 04 81 fa 00 02 20 00 74 33 <8b> 12 39 d0 75 5c 8b 10 8b 4a 04 39 c8 0f 85 b5 00 00 00 8b 48
EIP: [<c11dd7bd>] list_del+0x1d/0x120 SS:ESP 0068:f600bf3c
CR2: 0000000000200200
---[ end trace efd9a11434f00831 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Pid: 3, comm: ksoftirqd/0 Tainted: G      D W   2.6.37+ #39
Call Trace:
 [<c13fede1>] ? printk+0x1d/0x24
 [<c13fecce>] panic+0x66/0x15c
 [<c10067df>] oops_end+0x8f/0x90
 [<c1025476>] no_context+0xc6/0x160
 [<c10255a8>] __bad_area_nosemaphore+0x98/0x140
 [<c103cf68>] ? release_console_sem+0x1d8/0x210
 [<c1025667>] bad_area_nosemaphore+0x17/0x20
 [<c1025a49>] do_page_fault+0x279/0x420
 [<c1006a8f>] ? show_trace+0x1f/0x30
 [<c13fede1>] ? printk+0x1d/0x24
 [<c10257d0>] ? do_page_fault+0x0/0x420
 [<c140333b>] error_code+0x5f/0x64
 [<c103007b>] ? select_task_rq_fair+0x37b/0x6a0
 [<c10257d0>] ? do_page_fault+0x0/0x420
 [<c11dd7bd>] ? list_del+0x1d/0x120
 [<f8051fac>] acm_rx_tasklet+0x2dc/0x3e0 [cdc_acm]
 [<c106dbab>] ? trace_hardirqs_on+0xb/0x10
 [<c1042b30>] ? tasklet_action+0x60/0x140
 [<c1042bb6>] tasklet_action+0xe6/0x140
 [<c104342f>] __do_softirq+0xaf/0x210
 [<c1043380>] ? __do_softirq+0x0/0x210
 <IRQ>  [<c1042c9a>] ? run_ksoftirqd+0x8a/0x1c0
 [<c1042c10>] ? run_ksoftirqd+0x0/0x1c0
 [<c105ac24>] ? kthread+0x74/0x80
 [<c105abb0>] ? kthread+0x0/0x80
 [<c100337a>] ? kernel_thread_helper+0x6/0x10
panic occurred, switching back to text console
------------[ cut here ]------------

Cc: stable <stable@kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index f492a7f2b6e..00d809dfe84 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -646,8 +646,10 @@ static void acm_port_down(struct acm *acm)
 		usb_kill_urb(acm->ctrlurb);
 		for (i = 0; i < ACM_NW; i++)
 			usb_kill_urb(acm->wb[i].urb);
+		tasklet_disable(&acm->urb_task);
 		for (i = 0; i < nr; i++)
 			usb_kill_urb(acm->ru[i].urb);
+		tasklet_enable(&acm->urb_task);
 		acm->control->needs_remote_wakeup = 0;
 		usb_autopm_put_interface(acm->control);
 	}