| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 25/94] usb: wusbcore: security: cast sizeof to int for comparison | Date | Tue, 2 Oct 2018 06:24:39 -0700 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Julia Lawall <Julia.Lawall@lip6.fr>
[ Upstream commit d3ac5598c5010a8999978ebbcca3b1c6188ca36b ]
Comparing an int to a size, which is unsigned, causes the int to become unsigned, giving the wrong result. usb_get_descriptor can return a negative error code.
A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/)
// <smpl> @@ int x; expression e,e1; identifier f; @@
*x = f(...); ... when != x = e1 when != if (x < 0 || ...) { ... return ...; } *x < sizeof(e) // </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/usb/wusbcore/security.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/wusbcore/security.c +++ b/drivers/usb/wusbcore/security.c @@ -230,7 +230,7 @@ int wusb_dev_sec_add(struct wusbhc *wusb result = usb_get_descriptor(usb_dev, USB_DT_SECURITY, 0, secd, sizeof(*secd)); - if (result < sizeof(*secd)) { + if (result < (int)sizeof(*secd)) { dev_err(dev, "Can't read security descriptor or " "not enough data: %d\n", result); goto out;
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