6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hui Su <redacted>
commit 649bc7df3e5d7be6f7996a95084037dbf3cad1e5 upstream.
event_test_stuff() calls kthread_run() and unconditionally passes the
returned task_struct pointer to kthread_stop(). kthread_run() returns an
error pointer such as ERR_PTR(-ENOMEM) when kthread creation fails, for
example under memory pressure during the boot-time event self-test.
kthread_stop() then dereferences the invalid pointer, crashing the kernel.
Check the result of kthread_run() before passing it to kthread_stop(). Use
WARN_ON() so that a failure to create the self-test thread does not go
unnoticed, matching the ring-buffer self-test fix in commit
91542863abad ("ring-buffer: Fix crash passing ERR_PTR to kthread_stop()").
Cc: <redacted>
Fixes: e6187007d6c3 ("tracing/events: add startup tests for events")
Link: https://patch.msgid.link/20260817120642.668375-3-sh_def@163.com (local)
Signed-off-by: Hui Su <redacted>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace_events.c | 2 ++
1 file changed, 2 insertions(+)
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -4071,6 +4071,8 @@ static __init void event_test_stuff(void
struct task_struct *test_thread;
test_thread = kthread_run(event_test_thread, NULL, "test-events");
+ if (WARN_ON(IS_ERR(test_thread)))
+ return;
msleep(1);
kthread_stop(test_thread);
}