6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx> commit 6a75f19af16ff482cfd6085c77123aa0f464f8dd upstream. The sysctl tests for vm.memfd_noexec rely on the kernel to support PID namespaces (i.e. the kernel is built with CONFIG_PID_NS=y). If the kernel the test runs on does not support PID namespaces, the first sysctl test will fail when attempting to spawn a new thread in a new PID namespace, abort the test, preventing the remaining tests from being run. This is not desirable, as not all kernels need PID namespaces, but can still use the other features provided by memfd. Therefore, only run the sysctl tests if the kernel supports PID namespaces. Otherwise, skip those tests and emit an informative message to let the user know why the sysctl tests are not being run. Link: https://lkml.kernel.org/r/20241205192943.3228757-1-isaacmanjarres@xxxxxxxxxx Fixes: 11f75a01448f ("selftests/memfd: add tests for MFD_NOEXEC_SEAL MFD_EXEC") Signed-off-by: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx> Reviewed-by: Jeff Xu <jeffxu@xxxxxxxxxx> Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx> Cc: Kalesh Singh <kaleshsingh@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [6.6+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/memfd/memfd_test.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- a/tools/testing/selftests/memfd/memfd_test.c +++ b/tools/testing/selftests/memfd/memfd_test.c @@ -9,6 +9,7 @@ #include <fcntl.h> #include <linux/memfd.h> #include <sched.h> +#include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <signal.h> @@ -1567,6 +1568,11 @@ static void test_share_fork(char *banner close(fd); } +static bool pid_ns_supported(void) +{ + return access("/proc/self/ns/pid", F_OK) == 0; +} + int main(int argc, char **argv) { pid_t pid; @@ -1601,8 +1607,12 @@ int main(int argc, char **argv) test_seal_grow(); test_seal_resize(); - test_sysctl_simple(); - test_sysctl_nested(); + if (pid_ns_supported()) { + test_sysctl_simple(); + test_sysctl_nested(); + } else { + printf("PID namespaces are not supported; skipping sysctl tests\n"); + } test_share_dup("SHARE-DUP", ""); test_share_mmap("SHARE-MMAP", "");
