From e540ad97e73cefb41e93d0c06d0fe6a8620a77e0 Mon Sep 17 00:00:00 2001 From: Rodrigo Campos Date: Mon, 17 May 2021 12:39:08 -0700 Subject: selftests/seccomp: Add test for atomic addfd+send This just adds a test to verify that when using the new introduced flag to ADDFD, a valid fd is added and returned as the syscall result. Signed-off-by: Rodrigo Campos Signed-off-by: Sargun Dhillon Acked-by: Tycho Andersen Acked-by: Christian Brauner Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210517193908.3113-5-sargun@sargun.me --- tools/testing/selftests/seccomp/seccomp_bpf.c | 38 +++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 98c3b647f54d..e2ba7adc2694 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -235,6 +235,10 @@ struct seccomp_notif_addfd { }; #endif +#ifndef SECCOMP_ADDFD_FLAG_SEND +#define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */ +#endif + struct seccomp_notif_addfd_small { __u64 id; char weird[4]; @@ -3976,8 +3980,14 @@ TEST(user_notification_addfd) ASSERT_GE(pid, 0); if (pid == 0) { + /* fds will be added and this value is expected */ if (syscall(__NR_getppid) != USER_NOTIF_MAGIC) exit(1); + + /* Atomic addfd+send is received here. Check it is a valid fd */ + if (fcntl(syscall(__NR_getppid), F_GETFD) == -1) + exit(1); + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); } @@ -4056,6 +4066,30 @@ TEST(user_notification_addfd) ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); ASSERT_EQ(addfd.id, req.id); + /* Verify we can do an atomic addfd and send */ + addfd.newfd = 0; + addfd.flags = SECCOMP_ADDFD_FLAG_SEND; + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); + + /* Child has fds 0-6 and 42 used, we expect the lower fd available: 7 */ + EXPECT_EQ(fd, 7); + EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); + + /* + * This sets the ID of the ADD FD to the last request plus 1. The + * notification ID increments 1 per notification. + */ + addfd.id = req.id + 1; + + /* This spins until the underlying notification is generated */ + while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && + errno != -EINPROGRESS) + nanosleep(&delay, NULL); + + memset(&req, 0, sizeof(req)); + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + ASSERT_EQ(addfd.id, req.id); + resp.id = req.id; resp.error = 0; resp.val = USER_NOTIF_MAGIC; @@ -4116,6 +4150,10 @@ TEST(user_notification_addfd_rlimit) EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); EXPECT_EQ(errno, EMFILE); + addfd.flags = SECCOMP_ADDFD_FLAG_SEND; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EMFILE); + addfd.newfd = 100; addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); -- cgit