diff options
| author | Andy Lutomirski <luto@kernel.org> | 2015-09-04 17:00:43 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-09-05 09:01:16 +0200 |
| commit | 76fc5e7b2355af167dea1a32e93c57fc37900a5b (patch) | |
| tree | 0db0ca6a7f1a689a7efdcf1539bacf330cc1715c /tools | |
| parent | 95cd2ea7d54b41b0b2828587f108fe270d59eede (diff) | |
x86/vm86: Block non-root vm86(old) if mmap_min_addr != 0
vm86 exposes an interesting attack surface against the entry
code. Since vm86 is mostly useless anyway if mmap_min_addr != 0,
just turn it off in that case.
There are some reports that vbetool can work despite setting
mmap_min_addr to zero. This shouldn't break that use case,
as CAP_SYS_RAWIO already overrides mmap_min_addr.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/x86/entry_from_vm86.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/tools/testing/selftests/x86/entry_from_vm86.c b/tools/testing/selftests/x86/entry_from_vm86.c index 9a43a59a9bb4..421c607a8856 100644 --- a/tools/testing/selftests/x86/entry_from_vm86.c +++ b/tools/testing/selftests/x86/entry_from_vm86.c @@ -116,8 +116,9 @@ static bool do_test(struct vm86plus_struct *v86, unsigned long eip, v86->regs.eip = eip; ret = vm86(VM86_ENTER, v86); - if (ret == -1 && errno == ENOSYS) { - printf("[SKIP]\tvm86 not supported\n"); + if (ret == -1 && (errno == ENOSYS || errno == EPERM)) { + printf("[SKIP]\tvm86 %s\n", + errno == ENOSYS ? "not supported" : "not allowed"); return false; } |