[PATCH 4.4 012/117] wlcore/wl12xx: spi: fix NULL pointer dereference (Oops)

Greg Kroah-Hartman
2016-02-14T22:25:56Z

From: Uri Mashiach <uri.mashiach@compulab.co.il>

commit e47301b06d5a65678690f04c2248fd181db1e59a upstream.

Fix the below Oops when trying to modprobe wlcore_spi.
The oops occurs because the wl1271_power_{off,on}()
function doesn't check the power() function pointer.

[ 23.401447] Unable to handle kernel NULL pointer dereference at
virtual address 00000000
[ 23.409954] pgd = c0004000
[ 23.412922] [00000000] *pgd=00000000
[ 23.416693] Internal error: Oops: 80000007 [#1] SMP ARM
[ 23.422168] Modules linked in: wl12xx wlcore mac80211 cfg80211
musb_dsps musb_hdrc usbcore usb_common snd_soc_simple_card evdev joydev
omap_rng wlcore_spi snd_soc_tlv320aic23_i2c rng_core snd_soc_tlv320aic23
c_can_platform c_can can_dev snd_soc_davinci_mcasp snd_soc_edma
snd_soc_omap omap_wdt musb_am335x cpufreq_dt thermal_sys hwmon
[ 23.453253] CPU: 0 PID: 36 Comm: kworker/0:2 Not tainted
4.2.0-00002-g951efee-dirty #233
[ 23.461720] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 23.468123] Workqueue: events request_firmware_work_func
[ 23.473690] task: de32efc0 ti: de4ee000 task.ti: de4ee000
[ 23.479341] PC is at 0x0
[ 23.482112] LR is at wl12xx_set_power_on+0x28/0x124 [wlcore]
[ 23.488074] pc : [<00000000>] lr : [<bf2581f0>] psr: 60000013
[ 23.488074] sp : de4efe50 ip : 00000002 fp : 00000000
[ 23.500162] r10: de7cdd00 r9 : dc848800 r8 : bf27af00
[ 23.505663] r7 : bf27a1a8 r6 : dcbd8a80 r5 : dce0e2e0 r4 :
dce0d2e0
[ 23.512536] r3 : 00000000 r2 : 00000000 r1 : 00000001 r0 :
dc848810
[ 23.519412] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM
Segment kernel
[ 23.527109] Control: 10c5387d Table: 9cb78019 DAC: 00000015
[ 23.533160] Process kworker/0:2 (pid: 36, stack limit = 0xde4ee218)
[ 23.539760] Stack: (0xde4efe50 to 0xde4f0000)

[...]

[ 23.665030] [<bf2581f0>] (wl12xx_set_power_on [wlcore]) from
[<bf25f7ac>] (wlcore_nvs_cb+0x118/0xa4c [wlcore])
[ 23.675604] [<bf25f7ac>] (wlcore_nvs_cb [wlcore]) from [<c04387ec>]
(request_firmware_work_func+0x30/0x58)
[ 23.685784] [<c04387ec>] (request_firmware_work_func) from
[<c0058e2c>] (process_one_work+0x1b4/0x4b4)
[ 23.695591] [<c0058e2c>] (process_one_work) from [<c0059168>]
(worker_thread+0x3c/0x4a4)
[ 23.704124] [<c0059168>] (worker_thread) from [<c005ee68>]
(kthread+0xd4/0xf0)
[ 23.711747] [<c005ee68>] (kthread) from [<c000f598>]
(ret_from_fork+0x14/0x3c)
[ 23.719357] Code: bad PC value
[ 23.722760] ---[ end trace 981be8510db9b3a9 ]---

Prevent oops by validationg power() pointer value before
calling the function.

Signed-off-by: Uri Mashiach <uri.mashiach@compulab.co.il>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/ti/wlcore/io.h | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/net/wireless/ti/wlcore/io.h
+++ b/drivers/net/wireless/ti/wlcore/io.h
@@ -207,19 +207,23 @@ static inline int __must_check wlcore_wr

static inline void wl1271_power_off(struct wl1271 *wl)
{
- int ret;
+ int ret = 0;

if (!test_bit(WL1271_FLAG_GPIO_POWER, &wl->flags))
return;

- ret = wl->if_ops->power(wl->dev, false);
+ if (wl->if_ops->power)
+ ret = wl->if_ops->power(wl->dev, false);
if (!ret)
clear_bit(WL1271_FLAG_GPIO_POWER, &wl->flags);
}

static inline int wl1271_power_on(struct wl1271 *wl)
{
- int ret = wl->if_ops->power(wl->dev, true);
+ int ret = 0;
+
+ if (wl->if_ops->power)
+ ret = wl->if_ops->power(wl->dev, true);
if (ret == 0)
set_bit(WL1271_FLAG_GPIO_POWER, &wl->flags);