From 6793b13c9aedea8e24cf429b924d6dabfd59e0d8 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) 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(-) diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c index f63dc6c150d2..00fd64cadf40 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; -- 2.39.5