diff --git a/src/libostree/ostree-bootloader-zipl.c b/src/libostree/ostree-bootloader-zipl.c index c0a2a14507..39de8de09e 100644 --- a/src/libostree/ostree-bootloader-zipl.c +++ b/src/libostree/ostree-bootloader-zipl.c @@ -35,6 +35,7 @@ #define SECURE_EXECUTION_LUKS_ROOT_KEY "/etc/luks/root" #define SECURE_EXECUTION_LUKS_BOOT_KEY "/etc/luks/boot" #define SECURE_EXECUTION_LUKS_CONFIG "/etc/crypttab" +#define SECURE_BOOT_SYSFS_FLAG "/sys/firmware/ipl/secure" #if !(defined HAVE_LIBARCHIVE) && defined(__s390x__) #error libarchive is required for s390x @@ -112,6 +113,52 @@ _ostree_bootloader_zipl_write_config (OstreeBootloader *bootloader, int bootvers return TRUE; } +static gboolean +_ostree_secure_boot_is_enabled (gboolean *out_enabled, GCancellable *cancellable, GError **error) +{ + *out_enabled = FALSE; + glnx_autofd int fd = -1; + if (!ot_openat_ignore_enoent (AT_FDCWD, SECURE_BOOT_SYSFS_FLAG, &fd, error)) + return FALSE; + if (fd != -1) + { + g_autofree char *data = glnx_fd_readall_utf8 (fd, NULL, cancellable, error); + if (!data) + return FALSE; + *out_enabled = strstr (data, "1") != NULL; + ot_journal_print (LOG_INFO, "s390x: sysfs: Secure Boot enabled: %d", *out_enabled); + return TRUE; + } + + // Fallback, RHEL 9 kernel is buggy and doesn't have sysfs flag. + // Let's check kmsg, with Secure Boot enabled kernel prints smth like: + // [ 0.027998] Linux version 5.14.0-284.36.1.el9_2.s390x + // [ 0.023193] setup: Linux is running as a z/VM guest operating system in 64-bit mode + // [ 0.023193] setup: Linux is running with Secure-IPL enabled + // [ 0.023194] setup: The IPL report contains the following components: + // [ 0.023194] setup: 0000000000009000 - 000000000000a000 (not signed) + // [ 0.023196] setup: 000000000000a000 - 000000000000e000 (signed, verified) + // [ 0.023197] setup: 0000000000010000 - 0000000000866000 (signed, verified) + // [ 0.023198] setup: 0000000000867000 - 0000000000868000 (not signed) + // [ 0.023199] setup: 0000000000877000 - 0000000000878000 (not signed) + // [ 0.023200] setup: 0000000000880000 - 0000000003f98000 (not signed) + fd = openat (AT_FDCWD, "/dev/kmsg", O_NONBLOCK | O_RDONLY); + if (fd == -1) + return glnx_throw_errno_prefix (error, "openat(/dev/kmsg)"); + unsigned max_lines = 5; // no need to read dozens of messages, ours comes really early + while (*out_enabled != TRUE && max_lines > 0) + { + char buf[1024]; + ssize_t len = read (fd, buf, sizeof (buf)); + if (len == -EAGAIN) + break; + *out_enabled = strstr (buf, "Secure-IPL enabled") != NULL; + --max_lines; + } + ot_journal_print (LOG_INFO, "s390x: kmsg: Secure Boot enabled: %d", *out_enabled); + return TRUE; +} + static gboolean _ostree_secure_execution_is_enabled (gboolean *out_enabled, GCancellable *cancellable, GError **error) @@ -408,7 +455,11 @@ _ostree_bootloader_zipl_post_bls_sync (OstreeBootloader *bootloader, int bootver return _ostree_secure_execution_enable (self, bootversion, keys, cancellable, error); } /* Fallback to non-SE setup */ - const char *const zipl_argv[] = { "zipl", NULL }; + gboolean sb_enabled = FALSE; + if (!_ostree_secure_boot_is_enabled (&sb_enabled, cancellable, error)) + return FALSE; + const char *const zipl_argv[] + = { "zipl", "--secure", (sb_enabled == TRUE) ? "1" : "auto", "-V", NULL }; int estatus; if (!g_spawn_sync (NULL, (char **)zipl_argv, NULL, G_SPAWN_SEARCH_PATH, NULL, NULL, NULL, NULL, &estatus, error))