rpms
/
systemd
7
0
Fork 0
Code Issues Pull Requests Releases Activity
systemd/0667-random-seed-handle-pos...

182 lines
8.9 KiB
Diff
Raw Permalink Blame History

From 4c15a3931701cca73d78bb09953e439e7125e020 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Wed, 16 Nov 2022 19:27:50 +0100
Subject: [PATCH] random-seed: handle post-merge review nits
These are various misc things that came up after merging.
(cherry picked from commit 3daeef088410cdddef622007f95b0a1b4a439532)
Related: RHEL-16952
---
src/boot/bootctl.c | 2 +-
src/boot/efi/random-seed.c | 6 ++--
src/random-seed/random-seed.c | 61 ++++++++++++++++++-----------------
3 files changed, 36 insertions(+), 33 deletions(-)
diff --git a/src/boot/bootctl.c b/src/boot/bootctl.c
index e23a72fd38..8d45e11c2b 100644
--- a/src/boot/bootctl.c
+++ b/src/boot/bootctl.c
@@ -1983,7 +1983,7 @@ static int verb_list(int argc, char *argv[], void *userdata) {
static int install_random_seed(const char *esp) {
_cleanup_(unlink_and_freep) char *tmp = NULL;
- unsigned char buffer[RANDOM_EFI_SEED_SIZE];
+ uint8_t buffer[RANDOM_EFI_SEED_SIZE];
_cleanup_free_ char *path = NULL;
_cleanup_close_ int fd = -1;
size_t token_size;
diff --git a/src/boot/efi/random-seed.c b/src/boot/efi/random-seed.c
index c723160c0f..e11e345e88 100644
--- a/src/boot/efi/random-seed.c
+++ b/src/boot/efi/random-seed.c
@@ -60,7 +60,6 @@ static EFI_STATUS acquire_system_token(void **ret, UINTN *ret_size) {
assert(ret);
assert(ret_size);
- *ret_size = 0;
err = efivar_get_raw(LOADER_GUID, L"LoaderSystemToken", &data, &size);
if (err != EFI_SUCCESS) {
if (err != EFI_NOT_FOUND)
@@ -192,6 +191,7 @@ EFI_STATUS process_random_seed(EFI_FILE *root_dir) {
/* Get some system specific seed that the installer might have placed in an EFI variable. We include
* it in our hash. This is protection against golden master image sloppiness, and it remains on the
* system, even when disk images are duplicated or swapped out. */
+ size = 0;
err = acquire_system_token(&system_token, &size);
if (mode != RANDOM_SEED_ALWAYS && (err != EFI_SUCCESS || size < DESIRED_SEED_SIZE) && !seeded_by_efi)
return err;
@@ -251,6 +251,7 @@ EFI_STATUS process_random_seed(EFI_FILE *root_dir) {
size = sizeof(uefi_monotonic_counter);
sha256_process_bytes(&size, sizeof(size), &hash);
sha256_process_bytes(&uefi_monotonic_counter, size, &hash);
+
err = RT->GetTime(&now, NULL);
size = err == EFI_SUCCESS ? sizeof(now) : 0; /* Known to be flaky, so don't bark on error. */
sha256_process_bytes(&size, sizeof(size), &hash);
@@ -300,7 +301,8 @@ EFI_STATUS process_random_seed(EFI_FILE *root_dir) {
if (err != EFI_SUCCESS)
return log_error_status_stall(err, L"Failed to flush random seed file: %r", err);
- err = BS->AllocatePool(EfiACPIReclaimMemory, sizeof(*new_seed_table) + DESIRED_SEED_SIZE,
+ err = BS->AllocatePool(EfiACPIReclaimMemory,
+ offsetof(struct linux_efi_random_seed, seed) + DESIRED_SEED_SIZE,
(void **) &new_seed_table);
if (err != EFI_SUCCESS)
return log_error_status_stall(err, L"Failed to allocate EFI table for random seed: %r", err);
diff --git a/src/random-seed/random-seed.c b/src/random-seed/random-seed.c
index 54ec3aa7d5..ab1f942289 100644
--- a/src/random-seed/random-seed.c
+++ b/src/random-seed/random-seed.c
@@ -321,9 +321,10 @@ static int refresh_boot_seed(void) {
struct sha256_ctx hash_state;
_cleanup_free_ void *seed_file_bytes = NULL;
_cleanup_free_ char *esp_path = NULL;
- _cleanup_close_ int seed_fd = -1;
+ _cleanup_close_ int seed_fd = -1, dir_fd = -1;
size_t len;
- ssize_t r;
+ ssize_t n;
+ int r;
assert_cc(RANDOM_EFI_SEED_SIZE == SHA256_DIGEST_SIZE);
@@ -337,48 +338,48 @@ static int refresh_boot_seed(void) {
return r; /* find_esp_and_warn() already logged */
}
- seed_fd = chase_symlinks_and_open("/loader/random-seed", esp_path,
- CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS,
- O_RDWR|O_CLOEXEC|O_NOCTTY, NULL);
- if (seed_fd == -ENOENT) {
+ r = chase_symlinks("/loader", esp_path, CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS, NULL, &dir_fd);
+ if (r < 0) {
+ if (r == -ENOENT) {
+ log_debug_errno(r, "Couldn't find ESP loader directory, so not updating ESP random seed.");
+ return 0;
+ }
+ return log_error_errno(r, "Failed to open ESP loader directory: %m");
+ }
+ seed_fd = openat(dir_fd, "random-seed", O_NOFOLLOW|O_RDWR|O_CLOEXEC|O_NOCTTY);
+ if (seed_fd < 0 && errno == ENOENT) {
uint64_t features;
-
r = efi_loader_get_features(&features);
- if (r == 0 && FLAGS_SET(features, EFI_LOADER_FEATURE_RANDOM_SEED)) {
- int dir_fd = chase_symlinks_and_open("/loader", esp_path,
- CHASE_PREFIX_ROOT|CHASE_PROHIBIT_SYMLINKS,
- O_DIRECTORY|O_CLOEXEC|O_NOCTTY, NULL);
- if (dir_fd >= 0) {
- seed_fd = openat(dir_fd, "random-seed", O_CREAT|O_EXCL|O_RDWR|O_CLOEXEC|O_NOCTTY, 0600);
- close(dir_fd);
- }
+ if (r == 0 && FLAGS_SET(features, EFI_LOADER_FEATURE_RANDOM_SEED))
+ seed_fd = openat(dir_fd, "random-seed", O_CREAT|O_EXCL|O_RDWR|O_CLOEXEC|O_NOCTTY, 0600);
+ else {
+ log_debug_errno(seed_fd, "Couldn't find ESP random seed, and not booted with systemd-boot, so not updating ESP random seed.");
+ return 0;
}
}
- if (seed_fd < 0) {
- log_debug_errno(seed_fd, "Failed to open EFI seed path: %m");
- return 0;
- }
+ if (seed_fd < 0)
+ return log_error_errno(errno, "Failed to open EFI seed path: %m");
r = random_seed_size(seed_fd, &len);
if (r < 0)
return log_error_errno(r, "Failed to determine EFI seed path length: %m");
seed_file_bytes = malloc(len);
if (!seed_file_bytes)
return log_oom();
- r = loop_read(seed_fd, seed_file_bytes, len, false);
- if (r < 0)
- return log_error_errno(r, "Failed to read EFI seed file: %m");
+ n = loop_read(seed_fd, seed_file_bytes, len, false);
+ if (n < 0)
+ return log_error_errno(n, "Failed to read EFI seed file: %m");
/* Hash the old seed in so that we never regress in entropy. */
sha256_init_ctx(&hash_state);
- sha256_process_bytes(&r, sizeof(r), &hash_state);
- sha256_process_bytes(seed_file_bytes, r, &hash_state);
+ sha256_process_bytes(&n, sizeof(n), &hash_state);
+ sha256_process_bytes(seed_file_bytes, n, &hash_state);
/* We're doing this opportunistically, so if the seeding dance before didn't manage to initialize the
* RNG, there's no point in doing it here. Secondly, getrandom(GRND_NONBLOCK) has been around longer
* than EFI seeding anyway, so there's no point in having non-getrandom() fallbacks here. So if this
* fails, just return early to cut our losses. */
- r = getrandom(buffer, sizeof(buffer), GRND_NONBLOCK);
- if (r < 0) {
+ n = getrandom(buffer, sizeof(buffer), GRND_NONBLOCK);
+ if (n < 0) {
if (errno == EAGAIN) {
log_debug_errno(errno, "Random pool not initialized yet, so skipping EFI seed update");
return 0;
@@ -389,11 +390,11 @@ static int refresh_boot_seed(void) {
}
return log_error_errno(errno, "Failed to generate random bytes for EFI seed: %m");
}
- assert(r == sizeof(buffer));
+ assert(n == sizeof(buffer));
/* Hash the new seed into the state containing the old one to generate our final seed. */
- sha256_process_bytes(&r, sizeof(r), &hash_state);
- sha256_process_bytes(buffer, r, &hash_state);
+ sha256_process_bytes(&n, sizeof(n), &hash_state);
+ sha256_process_bytes(buffer, n, &hash_state);
sha256_finish_ctx(&hash_state, buffer);
if (lseek(seed_fd, 0, SEEK_SET) < 0)
@@ -405,7 +406,7 @@ static int refresh_boot_seed(void) {
return log_error_errno(errno, "Failed to truncate EFI seed file: %m");
r = fsync_full(seed_fd);
if (r < 0)
- return log_error_errno(errno, "Failed to fsync EFI seed file: %m");
+ return log_error_errno(r, "Failed to fsync EFI seed file: %m");
log_debug("Updated random seed in ESP");
return 0;
Reference in New Issue View Git Blame Copy Permalink