From 92b0abf80c5c5f0e0d71d1309688a330fd74731b Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Wed, 28 Mar 2012 09:30:50 +0200 Subject: [PATCH] usb: gadget: eliminate NULL pointer dereference (bugfix) 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 Cc: stable@vger.kernel.org Signed-off-by: Felipe Balbi --- drivers/usb/gadget/f_fs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c index d187ae73262b..f52cb1ae45d9 100644 --- a/drivers/usb/gadget/f_fs.c +++ b/drivers/usb/gadget/f_fs.c @@ -712,7 +712,7 @@ static long ffs_ep0_ioctl(struct file *file, unsigned code, unsigned long value) 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; -- 2.30.2