From: Jiri Slaby <[email protected]> commit cb174681a9ececa6702f114b85bdf82144b6a5af upstream.
[ Backport to .32.y by Antonio Ospite <[email protected]> ] 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 <[email protected]> Signed-off-by: Jiri Kosina <[email protected]> Cc: Greg KH <[email protected]> Signed-off-by: Antonio Ospite <[email protected]> --- drivers/hid/hidraw.c | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index cdd1369..61da443 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -207,11 +207,14 @@ 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); @@ -225,10 +228,12 @@ 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, -- 1.7.2.3 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
