linux/drivers/input
Chen Hong 5b50e0e74e Input: i8042 - fix crash at boot time
commit 340d394a78 upstream.

The driver checks port->exists twice in i8042_interrupt(), first when
trying to assign temporary "serio" variable, and second time when deciding
whether it should call serio_interrupt(). The value of port->exists may
change between the 2 checks, and we may end up calling serio_interrupt()
with a NULL pointer:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
IP: [<ffffffff8150feaf>] _spin_lock_irqsave+0x1f/0x40
PGD 0
Oops: 0002 [#1] SMP
last sysfs file:
CPU 0
Modules linked in:

Pid: 1, comm: swapper Not tainted 2.6.32-358.el6.x86_64 #1 QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:[<ffffffff8150feaf>]  [<ffffffff8150feaf>] _spin_lock_irqsave+0x1f/0x40
RSP: 0018:ffff880028203cc0  EFLAGS: 00010082
RAX: 0000000000010000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000282 RSI: 0000000000000098 RDI: 0000000000000050
RBP: ffff880028203cc0 R08: ffff88013e79c000 R09: ffff880028203ee0
R10: 0000000000000298 R11: 0000000000000282 R12: 0000000000000050
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000098
FS:  0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000050 CR3: 0000000001a85000 CR4: 00000000001407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper (pid: 1, threadinfo ffff88013e79c000, task ffff88013e79b500)
Stack:
ffff880028203d00 ffffffff813de186 ffffffffffffff02 0000000000000000
<d> 0000000000000000 0000000000000000 0000000000000000 0000000000000098
<d> ffff880028203d70 ffffffff813e0162 ffff880028203d20 ffffffff8103b8ac
Call Trace:
<IRQ>
 [<ffffffff813de186>] serio_interrupt+0x36/0xa0
[<ffffffff813e0162>] i8042_interrupt+0x132/0x3a0
[<ffffffff8103b8ac>] ? kvm_clock_read+0x1c/0x20
[<ffffffff8103b8b9>] ? kvm_clock_get_cycles+0x9/0x10
[<ffffffff810e1640>] handle_IRQ_event+0x60/0x170
[<ffffffff8103b154>] ? kvm_guest_apic_eoi_write+0x44/0x50
[<ffffffff810e3d8e>] handle_edge_irq+0xde/0x180
[<ffffffff8100de89>] handle_irq+0x49/0xa0
[<ffffffff81516c8c>] do_IRQ+0x6c/0xf0
[<ffffffff8100b9d3>] ret_from_intr+0x0/0x11
[<ffffffff81076f63>] ? __do_softirq+0x73/0x1e0
[<ffffffff8109b75b>] ? hrtimer_interrupt+0x14b/0x260
[<ffffffff8100c1cc>] ? call_softirq+0x1c/0x30
[<ffffffff8100de05>] ? do_softirq+0x65/0xa0
[<ffffffff81076d95>] ? irq_exit+0x85/0x90
[<ffffffff81516d80>] ? smp_apic_timer_interrupt+0x70/0x9b
[<ffffffff8100bb93>] ? apic_timer_interrupt+0x13/0x20

To avoid the issue let's change the second check to test whether serio is
NULL or not.

Also, let's take i8042_lock in i8042_start() and i8042_stop() instead of
trying to be overly smart and using memory barriers.

Signed-off-by: Chen Hong <chenhong3@huawei.com>
[dtor: take lock in i8042_start()/i8042_stop()]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2017-07-27 15:08:05 -07:00
..
gameport x86/asm/tsc: Rename native_read_tsc() to rdtsc() 2015-07-06 15:23:28 +02:00
joystick Input: xpad - add support for Razer Wildcat gamepad 2017-04-21 09:31:19 +02:00
keyboard Input: gpio_keys - add support for GPIO descriptors 2017-04-12 12:41:19 +02:00
misc Input: cm109 - validate number of endpoints before using them 2017-03-30 09:41:23 +02:00
mouse Input: elantech - add Fujitsu Lifebook E546/E557 to force crc_enabled 2017-06-14 15:06:00 +02:00
rmi4 Input: synaptics-rmi4 - unlock on error 2017-01-12 11:39:26 +01:00
serio Input: i8042 - fix crash at boot time 2017-07-27 15:08:05 -07:00
tablet Input: kbtab - validate number of endpoints before using them 2017-03-30 09:41:23 +02:00
touchscreen Input: sur40 - validate number of endpoints before using them 2017-03-30 09:41:23 +02:00
apm-power.c Input: random formatting fixes 2012-08-21 22:29:49 -07:00
evbug.c Input: use pr_fmt and pr_<level> 2010-11-30 23:10:26 -08:00
evdev.c Input: evdev - fix bug in checking duplicate clock change request 2015-10-31 10:35:02 -07:00
ff-core.c Input: document and check on implicitly defined FF_MAX_EFFECTS 2015-10-16 15:32:16 -07:00
ff-memless.c [media] fixp-arith: replace sin/cos table by a better precision one 2015-03-02 14:50:06 -03:00
input-compat.c drivers/input: eliminate INPUT_COMPAT_TEST macro 2016-03-25 16:37:42 -07:00
input-compat.h drivers/input: eliminate INPUT_COMPAT_TEST macro 2016-03-25 16:37:42 -07:00
input-leds.c Input: LEDs - skip unnamed LEDs 2015-07-24 09:11:01 -07:00
input-mt.c Input: update input_mt_report_pointer_emulation to support hovering 2016-06-01 14:21:10 -07:00
input-polldev.c Input: implement managed polled input devices 2014-05-14 16:40:04 -07:00
input.c Merge branch 'for-linus' into next 2016-07-19 11:02:56 -07:00
joydev.c Input: joydev - recognize devices with Z axis as joysticks 2016-09-26 20:03:06 -07:00
Kconfig Input: synaptics-rmi4 - add support for Synaptics RMI4 devices 2016-03-10 16:02:39 -08:00
Makefile Input: synaptics-rmi4 - add support for Synaptics RMI4 devices 2016-03-10 16:02:39 -08:00
matrix-keymap.c input: Export matrix_keypad_parse_of_params() 2013-04-19 00:31:13 +02:00
mousedev.c Input: mousedev - fix race when creating mixed device 2014-03-29 14:44:23 -07:00
sparse-keymap.c treewide: Fix typo in Documentation/DocBook 2014-02-19 14:58:17 +01:00