From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120424223255.456705238@linuxfoundation.org> Date: Tue, 24 Apr 2012 15:33:16 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Andrzej Pietrasiewicz , Kyungmin Park , Felipe Balbi Subject: [ 23/42] usb: gadget: eliminate NULL pointer dereference (bugfix) In-Reply-To: <20120424223311.GA8456@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrzej Pietrasiewicz commit 92b0abf80c5c5f0e0d71d1309688a330fd74731b upstream. usb: gadget: eliminate NULL pointer dereference (bugfix) This patch fixes a bug which causes NULL pointer dereference in ffs_ep0_ioctl. The bug happens when the FunctionFS is not bound (either has not been bound yet or has been bound and then unbound) and can be reproduced with running the following commands: $ insmod g_ffs.ko $ mount -t functionfs func /dev/usbgadget $ ./null where null.c is: #include #include int main(void) { int fd = open("/dev/usbgadget/ep0", O_RDWR); ioctl(fd, FUNCTIONFS_CLEAR_HALT); return 0; } Signed-off-by: Andrzej Pietrasiewicz Signed-off-by: Kyungmin Park Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/f_fs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/usb/gadget/f_fs.c +++ b/drivers/usb/gadget/f_fs.c @@ -720,7 +720,7 @@ static long ffs_ep0_ioctl(struct file *f if (code == FUNCTIONFS_INTERFACE_REVMAP) { struct ffs_function *func = ffs->func; ret = func ? ffs_func_revmap_intf(func, value) : -ENODEV; - } else if (gadget->ops->ioctl) { + } else if (gadget && gadget->ops->ioctl) { ret = gadget->ops->ioctl(gadget, code, value); } else { ret = -ENOTTY;