Merge tag 'printk-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Prevent a possible out-of-bound access and a use-after-free in rather
   theoretical situations

 - Make no_hash_pointers take effect early

 - Some fixes and clean up of the ratelimit KUnit test

* tag 'printk-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: Handle pre-enabled consoles in the top-level register_console()
  printk: Fix possible console use-after-free
  lib/tests: test_ratelimit: fix stress test thread lifecycle and leak
  lib/vsprintf: Make no_hash_pointers take effect early
This commit is contained in:
Linus Torvalds
2026-08-20 15:34:31 -07:00
3 changed files with 40 additions and 23 deletions
+19 -10
View File
@@ -68,7 +68,6 @@ static void test_ratelimit_smoke(struct kunit *test)
static struct ratelimit_state stressrl = RATELIMIT_STATE_INIT_FLAGS("stressrl", HZ / 10, 3,
RATELIMIT_MSG_ON_RELEASE);
static int doneflag;
static const int stress_duration = 2 * HZ;
struct stress_kthread {
@@ -84,9 +83,8 @@ static int test_ratelimit_stress_child(void *arg)
struct stress_kthread *sktp = arg;
set_user_nice(current, MAX_NICE);
WARN_ON_ONCE(!sktp->tp);
while (!READ_ONCE(doneflag)) {
while (!kthread_should_stop()) {
sktp->nattempts++;
if (___ratelimit(&stressrl, __func__))
sktp->nunlimited++;
@@ -105,26 +103,37 @@ static void test_ratelimit_stress(struct kunit *test)
const int n_stress_kthread = cpumask_weight(cpu_online_mask);
struct stress_kthread skt = { 0 };
struct stress_kthread *sktp = kzalloc_objs(*sktp, n_stress_kthread);
int n_started = 0;
KUNIT_EXPECT_NOT_NULL_MSG(test, sktp, "Memory allocation failure");
KUNIT_ASSERT_NOT_NULL_MSG(test, sktp, "Memory allocation failure");
for (i = 0; i < n_stress_kthread; i++) {
sktp[i].tp = kthread_run(test_ratelimit_stress_child, &sktp[i], "%s/%i",
"test_ratelimit_stress_child", i);
KUNIT_EXPECT_NOT_NULL_MSG(test, sktp, "kthread creation failure");
if (IS_ERR(sktp[i].tp)) {
KUNIT_FAIL(test, "kthread_run failed: %ld", PTR_ERR(sktp[i].tp));
goto out_stop;
}
n_started++;
pr_alert("Spawned test_ratelimit_stress_child %d\n", i);
}
schedule_timeout_idle(stress_duration);
WRITE_ONCE(doneflag, 1);
for (i = 0; i < n_stress_kthread; i++) {
out_stop:
for (i = 0; i < n_started; i++) {
kthread_stop(sktp[i].tp);
skt.nattempts += sktp[i].nattempts;
skt.nunlimited += sktp[i].nunlimited;
skt.nlimited += sktp[i].nlimited;
skt.nmissed += sktp[i].nmissed;
}
KUNIT_ASSERT_EQ_MSG(test, skt.nunlimited + skt.nlimited, skt.nattempts,
"Outcomes not equal to attempts");
KUNIT_ASSERT_EQ_MSG(test, skt.nlimited, skt.nmissed, "Misses not equal to limits");
if (n_started == n_stress_kthread) {
KUNIT_ASSERT_EQ_MSG(test, skt.nunlimited + skt.nlimited, skt.nattempts,
"Outcomes not equal to attempts");
KUNIT_ASSERT_EQ_MSG(test, skt.nlimited, skt.nmissed,
"Misses not equal to limits");
}
kfree(sktp);
}
static struct kunit_case ratelimit_test_cases[] = {
+4
View File
@@ -2360,6 +2360,9 @@ void __init hash_pointers_finalize(bool slub_debug)
static int __init hash_pointers_mode_parse(char *str)
{
/* Avoid stale no_hash_pointers state when hash_pointers overrides it */
no_hash_pointers = false;
if (!str) {
pr_warn("Hash pointers mode empty; falling back to auto.\n");
hash_pointers_mode = HASH_PTR_AUTO;
@@ -2369,6 +2372,7 @@ static int __init hash_pointers_mode_parse(char *str)
} else if (strcmp(str, "never") == 0) {
pr_info("Hash pointers mode set to never.\n");
hash_pointers_mode = HASH_PTR_NEVER;
no_hash_pointers = true;
} else if (strcmp(str, "always") == 0) {
pr_info("Hash pointers mode set to always.\n");
hash_pointers_mode = HASH_PTR_ALWAYS;