From 1cde501bb4655e98fb832194beb88ac73be5a05d Mon Sep 17 00:00:00 2001 From: Bruno Prémont Date: Sat, 31 Aug 2013 14:07:48 +0200 Subject: HID: picolcd: Prevent NULL pointer dereference on _remove() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: [] 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:[] EFLAGS: 00010292 CPU: 0 EIP is at picolcd_exit_framebuffer+0x1b/0x80 [hid_picolcd] Call Trace: [] picolcd_remove+0xcb/0x120 [hid_picolcd] [] hid_device_remove+0x59/0xc0 [] __device_release_driver+0x5a/0xb0 [] device_release_driver+0x1f/0x30 [] bus_remove_device+0x9d/0xd0 [] device_del+0xd5/0x150 [] hid_destroy_device+0x24/0x60 [] usbhid_disconnect+0x1b/0x40 ... Signed-off-by: Bruno Prémont Cc: stable@kernel.org Signed-off-by: Jiri Kosina --- drivers/hid/hid-picolcd_fb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/hid/hid-picolcd_fb.c') 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); -- cgit v1.2.3-59-g8ed1b