On Thu, Dec 6, 2018 at 3:50 PM Kees Cook keescook@chromium.org wrote:
Commit f149b3155744 ("signal: Never allocate siginfo for SIGKILL or SIGSTOP") means that the seccomp selftest cannot check si_pid under SIGSTOP anymore. Since it's believed[1] there are no other userspace things depending on the old behavior, this removes the behavioral check in the selftest, since it's more a "extra" sanity check (which turns out, maybe, not to have been useful to test).
[1] https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYe...
Reported-by: Tycho Andersen tycho@tycho.ws Suggested-by: Eric W. Biederman ebiederm@xmission.com Signed-off-by: Kees Cook keescook@chromium.org
Shuah, can you make sure that Linus gets this before v4.20 is released? Thanks!
Ping. Shuah, can you get this to Linus (or should I send it directly?)
Thanks!
-Kees
tools/testing/selftests/seccomp/seccomp_bpf.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index e1473234968d..c9a2abf8be1b 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -2731,9 +2731,14 @@ TEST(syscall_restart) ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); ASSERT_EQ(true, WIFSTOPPED(status)); ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
/* Verify signal delivery came from parent now. */ ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info));EXPECT_EQ(getpid(), info.si_pid);
/** There is no siginfo on SIGSTOP any more, so we can't verify* signal delivery came from parent now (getpid() == info.si_pid).* https://lkml.kernel.org/r/CAGXu5jJaZAOzP1qFz66tYrtbuywqb+UN2SOA1VLHpCCOiYvYeg@mail.gmail.com* At least verify the SIGSTOP via PTRACE_GETSIGINFO.*/EXPECT_EQ(SIGSTOP, info.si_signo); /* Restart nanosleep with SIGCONT, which triggers restart_syscall. */ ASSERT_EQ(0, kill(child_pid, SIGCONT));-- 2.17.1
-- Kees Cook