6.8-stable review patch. If anyone has any objections, please let me know.
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From: Terry Tritton terry.tritton@linaro.org
commit 8e3c9f9f3a0742cd12b682a1766674253b33fcf0 upstream.
Currently the user_notification_addfd test checks what the next expected file descriptor will be by incrementing a variable nextfd. This does not account for file descriptors that may already be open before the test is started and will cause the test to fail if any exist.
Replace nextfd++ with a function get_next_fd which will check and return the next available file descriptor.
Signed-off-by: Terry Tritton terry.tritton@linaro.org Link: https://lore.kernel.org/r/20240124141357.1243457-4-terry.tritton@linaro.org Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/testing/selftests/seccomp/seccomp_bpf.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-)
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -4037,6 +4037,16 @@ TEST(user_notification_filter_empty_thre EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); }
+ +int get_next_fd(int prev_fd) +{ + for (int i = prev_fd + 1; i < FD_SETSIZE; ++i) { + if (fcntl(i, F_GETFD) == -1) + return i; + } + _exit(EXIT_FAILURE); +} + TEST(user_notification_addfd) { pid_t pid; @@ -4053,7 +4063,7 @@ TEST(user_notification_addfd) /* There may be arbitrary already-open fds at test start. */ memfd = memfd_create("test", 0); ASSERT_GE(memfd, 0); - nextfd = memfd + 1; + nextfd = get_next_fd(memfd);
ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); ASSERT_EQ(0, ret) { @@ -4064,7 +4074,8 @@ TEST(user_notification_addfd) /* Check that the basic notification machinery works */ listener = user_notif_syscall(__NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER); - ASSERT_EQ(listener, nextfd++); + ASSERT_EQ(listener, nextfd); + nextfd = get_next_fd(nextfd);
pid = fork(); ASSERT_GE(pid, 0); @@ -4119,14 +4130,16 @@ TEST(user_notification_addfd)
/* Verify we can set an arbitrary remote fd */ fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); - EXPECT_EQ(fd, nextfd++); + EXPECT_EQ(fd, nextfd); + nextfd = get_next_fd(nextfd); EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
/* Verify we can set an arbitrary remote fd with large size */ memset(&big, 0x0, sizeof(big)); big.addfd = addfd; fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); - EXPECT_EQ(fd, nextfd++); + EXPECT_EQ(fd, nextfd); + nextfd = get_next_fd(nextfd);
/* Verify we can set a specific remote fd */ addfd.newfd = 42; @@ -4164,7 +4177,8 @@ TEST(user_notification_addfd) * Child has earlier "low" fds and now 42, so we expect the next * lowest available fd to be assigned here. */ - EXPECT_EQ(fd, nextfd++); + EXPECT_EQ(fd, nextfd); + nextfd = get_next_fd(nextfd); ASSERT_EQ(filecmp(getpid(), pid, memfd, fd), 0);
/*