From 7cbf7431e259aa462db37fbefc146fbf2a416805 Mon Sep 17 00:00:00 2001 From: Antonio Ospite Date: Tue, 5 Oct 2010 17:20:16 +0200 Subject: HID: hidraw, fix a NULL pointer dereference in hidraw_ioctl commit d20d5ffab92f00188f360c44c791a5ffb988247c upstream. BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [] hidraw_ioctl+0xfc/0x32c [hid] [...] This is reproducible by disconnecting the device while userspace does ioctl in a loop and doesn't check return values in order to exit the loop. Signed-off-by: Antonio Ospite Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hidraw.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index cdd136942bca..3b53475a2b3d 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -237,11 +237,16 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, struct inode *inode = file->f_path.dentry->d_inode; unsigned int minor = iminor(inode); long ret = 0; - /* FIXME: What stops hidraw_table going NULL */ - struct hidraw *dev = hidraw_table[minor]; + struct hidraw *dev; void __user *user_arg = (void __user*) arg; lock_kernel(); + dev = hidraw_table[minor]; + if (!dev) { + ret = -ENODEV; + goto out; + } + switch (cmd) { case HIDIOCGRDESCSIZE: if (put_user(dev->hid->rsize, (int __user *)arg)) @@ -314,6 +319,7 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, ret = -ENOTTY; } +out: unlock_kernel(); return ret; } -- cgit v1.2.3