From 24977195f50960222eb9ad2982e6cd252ff9f63f Mon Sep 17 00:00:00 2001 From: Antonio Ospite Date: Tue, 5 Oct 2010 17:20:16 +0200 Subject: [PATCH] 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. [PG: slightly/trivially reworked for backport to 34] Signed-off-by: Antonio Ospite Signed-off-by: Jiri Kosina Signed-off-by: Paul Gortmaker --- drivers/hid/hidraw.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 6eadf1a9b3cca..0db1a0f5d2a0d 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -243,6 +243,11 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, void __user *user_arg = (void __user*) arg; lock_kernel(); + if (!dev) { + ret = -ENODEV; + goto out; + } + switch (cmd) { case HIDIOCGRDESCSIZE: if (put_user(dev->hid->rsize, (int __user *)arg)) @@ -315,6 +320,7 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, ret = -ENOTTY; } +out: unlock_kernel(); return ret; } -- 2.47.3