[PATCH v3 2/7] kunit: Fix kthread reference
From: Mickaël Salaün <mic@digikod.net>
Date: 2024-03-19 10:55:34
Also in:
kvm, linux-hardening, linux-security-module, linux-um, lkml
Subsystem:
kernel unit testing framework (kunit), library code, the rest · Maintainers:
Brendan Higgins, David Gow, Andrew Morton, Linus Torvalds
There is a race condition when a kthread finishes after the deadline and
before the call to kthread_stop(), which may lead to use after free.
Cc: Brendan Higgins <redacted>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Kees Cook <redacted>
Fixes: adf505457032 ("kunit: fix UAF when run kfence test case test_gfpzero")
Reviewed-by: David Gow <redacted>
Reviewed-by: Rae Moar <redacted>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20240319104857.70783-3-mic@digikod.net (local)
---
Changes since v2:
* Add Fixes tag as suggested by David.
* Add David's and Rae's Reviewed-by.
Changes since v1:
* Add Kees's Reviewed-by.
---
lib/kunit/try-catch.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
index a5cb2ef70a25..73f5007f20ea 100644
--- a/lib/kunit/try-catch.c
+++ b/lib/kunit/try-catch.c@@ -11,6 +11,7 @@ #include <linux/completion.h> #include <linux/kernel.h> #include <linux/kthread.h> +#include <linux/sched/task.h> #include "try-catch-impl.h"
@@ -65,14 +66,15 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) try_catch->context = context; try_catch->try_completion = &try_completion; try_catch->try_result = 0; - task_struct = kthread_run(kunit_generic_run_threadfn_adapter, - try_catch, - "kunit_try_catch_thread"); + task_struct = kthread_create(kunit_generic_run_threadfn_adapter, + try_catch, "kunit_try_catch_thread"); if (IS_ERR(task_struct)) { try_catch->try_result = PTR_ERR(task_struct); try_catch->catch(try_catch->context); return; } + get_task_struct(task_struct); + wake_up_process(task_struct); time_remaining = wait_for_completion_timeout(&try_completion, kunit_test_timeout());
@@ -82,6 +84,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context) kthread_stop(task_struct); } + put_task_struct(task_struct); exit_code = try_catch->try_result; if (!exit_code)
--
2.44.0