diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-04-04 18:12:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-17 08:36:47 +0200 |
| commit | 356bcb7b4eaa2fb92332344b5d1c1e47103b6999 (patch) | |
| tree | 1f858c11ae833daf7d8b3ed39269aea3db1c1a2f | |
| parent | 79bedcb095bdc5c83db65180b414a8b0ac89b91d (diff) | |
xen: Prevent buffer overflow in privcmd ioctl
commit 42d8644bd77dd2d747e004e367cb0c895a606f39 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/include/asm/xen/hypercall.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index ccdc23d89b60..9f694537a103 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -216,6 +216,9 @@ privcmd_call(unsigned call, __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); + if (call >= PAGE_SIZE / sizeof(hypercall_page[0])) + return -EINVAL; + stac(); asm volatile(CALL_NOSPEC : __HYPERCALL_5PARAM |