Messages in this thread Patch in this message | | | Date | Mon, 7 Feb 2011 23:38:48 -0800 | From | Dmitry Torokhov <> | Subject | Re: [PATCH] uinput strnlen bugfix |
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On Sun, Feb 06, 2011 at 11:40:17PM -0800, Dmitry Torokhov wrote: > On Sun, Feb 06, 2011 at 12:23:17PM -0500, Aristeu Rozanski wrote: > > On Sun, Feb 06, 2011 at 05:57:19PM +0100, David Herrmann wrote: > > > On Sun, Feb 6, 2011 at 5:55 PM, Aristeu Rozanski <aris@cathedrallabs.org> wrote: > > > > and where's the patch? :^) > > > > > > > > -- > > > > Aristeu > > > > > > > > > > ah, embarrasing.., sorry. > > > I attached the patchfile. > > > > > > David > > > > > --- old/drivers/input/misc/uinput.c 2011-02-06 17:40:24.951454656 +0100 > > > +++ new/drivers/input/misc/uinput.c 2011-02-06 17:41:16.747454654 +0100 > > > @@ -372,8 +372,8 @@ > > > > > > udev->ff_effects_max = user_dev->ff_effects_max; > > > > > > - size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE) + 1; > > > - if (!size) { > > > + size = strnlen(user_dev->name, UINPUT_MAX_NAME_SIZE); > > > + if (!size++) { > > > retval = -EINVAL; > > > goto exit; > > > } > > Acked-by: Aristeu Rozanski <aris@ruivo.org> > > > > Hmm, not particularly fond with the construct, how about below instead? >
And while we are at it...
-- Dmitry
Input: uinput - use memdup_user() and friends
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Instead of open-coding copying of data structures from userspace use memdup_user() and strndup_user(). Note that this introduces change in behavior because driver used to truncate 'phys' longer than 1024 bytes, but now it will refuse to set 'phys' that long. Arguably trying to set such 'phys' is suspect anyways.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru> ---
drivers/input/misc/uinput.c | 35 ++++++++++------------------------- 1 files changed, 10 insertions(+), 25 deletions(-)
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index c0888e3..7f8331f 100644 --- a/drivers/input/misc/uinput.c +++ b/drivers/input/misc/uinput.c @@ -361,14 +361,9 @@ static int uinput_setup_device(struct uinput_device *udev, const char __user *bu dev = udev->dev; - user_dev = kmalloc(sizeof(struct uinput_user_dev), GFP_KERNEL); - if (!user_dev) - return -ENOMEM; - - if (copy_from_user(user_dev, buffer, sizeof(struct uinput_user_dev))) { - retval = -EFAULT; - goto exit; - } + user_dev = memdup_user(buffer, sizeof(struct uinput_user_dev)); + if (!IS_ERR(user_dev)) + return PTR_ERR(user_dev); udev->ff_effects_max = user_dev->ff_effects_max; @@ -621,7 +616,6 @@ static long uinput_ioctl_handler(struct file *file, unsigned int cmd, struct uinput_ff_upload ff_up; struct uinput_ff_erase ff_erase; struct uinput_request *req; - int length; char *phys; retval = mutex_lock_interruptible(&udev->mutex); @@ -688,24 +682,15 @@ static long uinput_ioctl_handler(struct file *file, unsigned int cmd, retval = -EINVAL; goto out; } - length = strnlen_user(p, 1024); - if (length <= 0) { - retval = -EFAULT; - break; + + phys = strndup_user(p, 1024); + if (IS_ERR(phys)) { + retval = PTR_ERR(phys); + goto out; } + kfree(udev->dev->phys); - udev->dev->phys = phys = kmalloc(length, GFP_KERNEL); - if (!phys) { - retval = -ENOMEM; - break; - } - if (copy_from_user(phys, p, length)) { - udev->dev->phys = NULL; - kfree(phys); - retval = -EFAULT; - break; - } - phys[length - 1] = '\0'; + udev->dev->phys = phys; break; case UI_BEGIN_FF_UPLOAD:
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