Messages in this thread Patch in this message | | | Date | Tue, 07 Dec 2010 16:44:40 -0800 | From | Greg KH <> | Subject | [094/127] HID: hidraw, fix a NULL pointer dereference in hidraw_ioctl |
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2.6.32-stable review patch. If anyone has any objections, please let us know.
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From: Antonio Ospite <ospite@studenti.unina.it>
commit d20d5ffab92f00188f360c44c791a5ffb988247c upstream.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [<ffffffffa02c66b4>] 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 <ospite@studenti.unina.it> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/hid/hidraw.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -237,11 +237,16 @@ static long hidraw_ioctl(struct file *fi 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 *fi ret = -ENOTTY; } +out: unlock_kernel(); return ret; }
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