Messages in this thread Patch in this message | | | From | Ben Hutchings <> | Date | Sat, 10 Aug 2019 21:40:07 +0100 | Subject | [PATCH 3.16 070/157] xen: Prevent buffer overflow in privcmd ioctl |
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3.16.72-rc1 review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter <dan.carpenter@oracle.com>
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.
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> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- arch/x86/include/asm/xen/hypercall.h | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -215,6 +215,9 @@ 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
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