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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-04-04 17:12:17 +0200 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2019-04-05 08:42:45 +0200 |
| commit | 42d8644bd77dd2d747e004e367cb0c895a606f39 (patch) | |
| tree | cd9e5755de282db44f8995eb87b6f3a134cf7ef7 | |
| parent | xen: use struct_size() helper in kzalloc() (diff) | |
| download | linux-42d8644bd77dd2d747e004e367cb0c895a606f39.tar.xz linux-42d8644bd77dd2d747e004e367cb0c895a606f39.zip | |
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>
| -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 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_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); + if (call >= PAGE_SIZE / sizeof(hypercall_page[0])) + return -EINVAL; + asm volatile(CALL_NOSPEC : __HYPERCALL_5PARAM : [thunk_target] "a" (&hypercall_page[call]) |