path: root/arch
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authorDan Carpenter <dan.carpenter@oracle.com>2019-04-04 18:12:17 +0300
committerJuergen Gross <jgross@suse.com>2019-04-05 08:42:45 +0200
commit42d8644bd77dd2d747e004e367cb0c895a606f39 (patch)
treecd9e5755de282db44f8995eb87b6f3a134cf7ef7 /arch
parentad94dc3a7eb5fa6ff469dbcf401c44b14ad50595 (diff)
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>
Diffstat (limited to 'arch')
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 de6f0d59a24f..2863c2026655 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -206,6 +206,9 @@ xen_single_call(unsigned int call,
__HYPERCALL_5ARG(a1, a2, a3, a4, a5);
+ if (call >= PAGE_SIZE / sizeof(hypercall_page[0]))
+ return -EINVAL;
asm volatile(CALL_NOSPEC
: [thunk_target] "a" (&hypercall_page[call])