From 32aba3cf35c2fd0dde82d1acac9c76424f576c67 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Tue, 19 Oct 2010 11:29:55 +0200 Subject: [PATCH] HID: hidraw: fix window in hidraw_release commit cb174681a9ececa6702f114b85bdf82144b6a5af upstream. [ Backport to .32.y by Antonio Ospite ] There is a window between hidraw_table check and its dereference. In that window, the device may be unplugged and removed form the system and we will then dereference NULL. Lock that place properly so that either we get NULL and jump out or we can work with real pointer. Signed-off-by: Jiri Slaby Signed-off-by: Jiri Kosina Signed-off-by: Antonio Ospite Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hidraw.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 66579c0bf328..5b57551233f4 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -211,11 +211,14 @@ static int hidraw_release(struct inode * inode, struct file * file) unsigned int minor = iminor(inode); struct hidraw *dev; struct hidraw_list *list = file->private_data; + int ret; + mutex_lock(&minors_lock); if (!hidraw_table[minor]) { printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", minor); - return -ENODEV; + ret = -ENODEV; + goto unlock; } list_del(&list->node); @@ -229,10 +232,12 @@ static int hidraw_release(struct inode * inode, struct file * file) kfree(list->hidraw); } } - kfree(list); + ret = 0; +unlock: + mutex_unlock(&minors_lock); - return 0; + return ret; } static long hidraw_ioctl(struct file *file, unsigned int cmd, -- 2.39.5