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| author | Bruno Prémont <bonbons@linux-vserver.org> | 2013-08-31 14:07:48 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2013-09-02 13:36:50 +0200 |
| commit | 1cde501bb4655e98fb832194beb88ac73be5a05d (patch) | |
| tree | 86cc70fe2cc7c5e4fa875a5ada657a3825056428 | |
| parent | 9e0bf92c223dabe0789714f8f85f6e26f8f9cda4 (diff) | |
| download | lwn-1cde501bb4655e98fb832194beb88ac73be5a05d.tar.gz lwn-1cde501bb4655e98fb832194beb88ac73be5a05d.zip | |
HID: picolcd: Prevent NULL pointer dereference on _remove()
When picolcd is switched into bootloader mode (for FW flashing) make
sure not to try to dereference NULL-pointers of feature-devices during
unplug/unbind.
This fixes following BUG:
BUG: unable to handle kernel NULL pointer dereference at 00000298
IP: [<f811f56b>] picolcd_exit_framebuffer+0x1b/0x80 [hid_picolcd]
*pde = 00000000
Oops: 0000 [#1]
Modules linked in: hid_picolcd syscopyarea sysfillrect sysimgblt fb_sys_fops
CPU: 0 PID: 15 Comm: khubd Not tainted 3.11.0-rc7-00002-g50d62d4 #2
EIP: 0060:[<f811f56b>] EFLAGS: 00010292 CPU: 0
EIP is at picolcd_exit_framebuffer+0x1b/0x80 [hid_picolcd]
Call Trace:
[<f811d1ab>] picolcd_remove+0xcb/0x120 [hid_picolcd]
[<c1469b09>] hid_device_remove+0x59/0xc0
[<c13464ca>] __device_release_driver+0x5a/0xb0
[<c134653f>] device_release_driver+0x1f/0x30
[<c134603d>] bus_remove_device+0x9d/0xd0
[<c13439a5>] device_del+0xd5/0x150
[<c14696a4>] hid_destroy_device+0x24/0x60
[<c1474cbb>] usbhid_disconnect+0x1b/0x40
...
Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Cc: stable@kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| -rw-r--r-- | drivers/hid/hid-picolcd_cir.c | 3 | ||||
| -rw-r--r-- | drivers/hid/hid-picolcd_fb.c | 6 |
2 files changed, 7 insertions, 2 deletions
diff --git a/drivers/hid/hid-picolcd_cir.c b/drivers/hid/hid-picolcd_cir.c index e346038f0f11..59d5eb1e742c 100644 --- a/drivers/hid/hid-picolcd_cir.c +++ b/drivers/hid/hid-picolcd_cir.c @@ -145,6 +145,7 @@ void picolcd_exit_cir(struct picolcd_data *data) struct rc_dev *rdev = data->rc_dev; data->rc_dev = NULL; - rc_unregister_device(rdev); + if (rdev) + rc_unregister_device(rdev); } diff --git a/drivers/hid/hid-picolcd_fb.c b/drivers/hid/hid-picolcd_fb.c index 591f6b22aa94..c930ab8554ea 100644 --- a/drivers/hid/hid-picolcd_fb.c +++ b/drivers/hid/hid-picolcd_fb.c @@ -593,10 +593,14 @@ err_nomem: void picolcd_exit_framebuffer(struct picolcd_data *data) { struct fb_info *info = data->fb_info; - struct picolcd_fb_data *fbdata = info->par; + struct picolcd_fb_data *fbdata; unsigned long flags; + if (!info) + return; + device_remove_file(&data->hdev->dev, &dev_attr_fb_update_rate); + fbdata = info->par; /* disconnect framebuffer from HID dev */ spin_lock_irqsave(&fbdata->lock, flags); |