From 6943ee7c9d83e9130038e575896c0cd974c93dcc Mon Sep 17 00:00:00 2001 From: Len Baker Date: Sat, 11 Sep 2021 13:26:31 +0200 Subject: [PATCH] usb: ohci: Prefer struct_size over open coded arithmetic As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the kzalloc() function. [1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Acked-by: Alan Stern Signed-off-by: Len Baker Link: https://lore.kernel.org/r/20210911112631.10004-1-len.baker@gmx.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ohci-hcd.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c index 1f5e69314a172..666b1c6651881 100644 --- a/drivers/usb/host/ohci-hcd.c +++ b/drivers/usb/host/ohci-hcd.c @@ -191,8 +191,7 @@ static int ohci_urb_enqueue ( } /* allocate the private part of the URB */ - urb_priv = kzalloc (sizeof (urb_priv_t) + size * sizeof (struct td *), - mem_flags); + urb_priv = kzalloc(struct_size(urb_priv, td, size), mem_flags); if (!urb_priv) return -ENOMEM; INIT_LIST_HEAD (&urb_priv->pending); -- 2.30.2