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author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-04-04 18:12:17 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-27 10:30:26 +0300 |
commit | cfa402909d9cf80d6526f2d54b39c3b8cbd5fff5 (patch) | |
tree | e7c9f5a38d0a01b4db3f8ea009458127f7cc576b /arch | |
parent | ab6ce574b2c97b09a2e5d2ba091f155f97a67b81 (diff) | |
download | linux-cfa402909d9cf80d6526f2d54b39c3b8cbd5fff5.tar.xz |
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>
Diffstat (limited to 'arch')
-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 ca08a27b90b3..6e1e86781d90 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -213,6 +213,9 @@ privcmd_call(unsigned call, __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); + if (call >= PAGE_SIZE / sizeof(hypercall_page[0])) + return -EINVAL; + asm volatile("call *%[call]" : __HYPERCALL_5PARAM : [call] "a" (&hypercall_page[call]) |