xen: Prevent buffer overflow in privcmd ioctl
authorDan Carpenter <dan.carpenter@oracle.com>
Thu, 4 Apr 2019 15:12:17 +0000 (18:12 +0300)
committerJuergen Gross <jgross@suse.com>
Fri, 5 Apr 2019 06:42:45 +0000 (08:42 +0200)
commit42d8644bd77dd2d747e004e367cb0c895a606f39
treecd9e5755de282db44f8995eb87b6f3a134cf7ef7
parentad94dc3a7eb5fa6ff469dbcf401c44b14ad50595
xen: Prevent buffer overflow in privcmd ioctl

The "call" variable comes from the user in privcmd_ioctl_hypercall().
It's an offset into the hypercall_page[] which has (PAGE_SIZE / 32)
elements.  We need to put an upper bound on it to prevent an out of
bounds access.

Cc: stable@vger.kernel.org
Fixes: 1246ae0bb992 ("xen: add variable hypercall caller")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
arch/x86/include/asm/xen/hypercall.h