From e4f51ee7c6f1a43f91cec2b364eb6a30fa66fdb0 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. 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. [PG: slightly/trivially reworked for backport to 34] Signed-off-by: Jiri Slaby Signed-off-by: Jiri Kosina Signed-off-by: Paul Gortmaker --- drivers/hid/hidraw.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 9d3c663dc8f4..23d936dfafa1 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -212,11 +212,12 @@ 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); @@ -230,10 +231,12 @@ 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