One problem with seccomp was that ptrace could be used to change a
syscall after seccomp filtering had completed. This was a well documented
limitation, and it was recommended to block ptrace when defining a filter
to avoid this problem. This can be quite a limitation for containers or
other places where ptrace is desired even under seccomp filters.
This adds tests for both SECCOMP_RET_TRACE and PTRACE_SYSCALL manipulations.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
By adding TRACEHOOK support we now get a clean user interface to access
registers via PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and
PTRACE_SETFPREGS.
The user-visible regset struct user_regs_struct and user_fp_struct are
modelled similiar to x86 and can be accessed via PTRACE_GETREGSET.
Signed-off-by: Helge Deller <deller@gmx.de>
This adds self-test support on MIPS, based on RFC patch from Kees Cook.
Modifications from the RFC:
- support the O32 syscall which passes the real syscall number in a0.
- Use PTRACE_{GET,SET}REGS
- Because SYSCALL_NUM and SYSCALL_RET are the same register, it is not
possible to test modifying the syscall return value when skipping,
since both would need to set the same register. Therefore modify that
test case to just detect the skipped test.
Tested on MIPS32r2 / MIPS64r2 with O32, N32 and N64 userlands.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Will Drewry <wad@chromium.org>
Cc: IMG-MIPSLinuxKerneldevelopers@imgtec.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12977/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Some architectures do not implement PTRACE_GETREGSET nor
PTRACE_SETREGSET (required by HAVE_ARCH_TRACEHOOK) but only implement
PTRACE_GETREGS and PTRACE_SETREGS (e.g. User-mode Linux).
This improve seccomp selftest portability for architectures without
HAVE_ARCH_TRACEHOOK support by defining a new trigger HAVE_GETREGS. For
now, this is only enabled for i386 and x86_64 architectures. This is
required to be able to run this tests on User-mode Linux.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: David Drysdale <drysdale@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Kees Cook <keescook@chromium.org>
The commit fd88d16c58 ("selftests/seccomp: Be more precise with
syscall arguments.") use PAGE_SIZE directly which lead to build
failure on arm64.
Replace it with generic interface(sysconf(_SC_PAGESIZE)) to fix this
failure.
Build and test successful on x86_64 and arm64.
Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Certain syscall emulation layers strictly check that the number of
arguments match what the syscall handler expects. The KILL_one_arg_one and
KILL_one_arg_six tests passed more parameters than expected to various
syscalls, causing failures in this emulation mode. Instead, test using
syscalls that take the appropriate number of arguments.
Signed-off-by: Robert Sesek <rsesek@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Changing arm64 syscalls is done via a specific register set, more like s390
than like arm (specific ptrace call) and x86 (part of general registers).
Since (restarting) poll doesn't exist on arm64, switch to using nanosleep
for testing restart_syscall. And since it looks like the syscall ABI is
inconsistent on arm-compat, so we must work around it (and document it) in
the test.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
This adds support for s390 to the seccomp selftests. Some improvements
were made to enhance the accuracy of failure reporting, and additional
tests were added to validate assumptions about the currently traced
syscall. Also adds early asserts for running on older kernels to avoid
noise when the seccomp syscall is not implemented.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Wire up the syscall number and regs so the tests work on powerpc.
With the powerpc kernel support just merged, all tests pass on ppc64,
ppc64 (compat), ppc64le, ppc, ppc64e and ppc64e (compat).
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The seccomp_bpf test uses BPF_LD|BPF_W|BPF_ABS to load 32-bit values
from seccomp_data->args. On big endian machines this will load the high
word of the argument, which is not what the test wants.
Borrow a hack from samples/seccomp/bpf-helper.h which changes the offset
on big endian to account for this.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Kees Cook <keescook@chromium.org>
This imports the existing seccomp test suite into the kernel's selftests
tree. It contains extensive testing of seccomp features and corner cases.
There remain additional tests to move into the kernel tree, but they have
not yet been ported to all the architectures seccomp supports:
https://github.com/redpig/seccomp/tree/master/tests
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Kees Cook