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 <brendanhigg...@google.com> Cc: David Gow <david...@google.com> Cc: Rae Moar <rm...@google.com> Cc: Shuah Khan <sk...@linuxfoundation.org> Reviewed-by: Kees Cook <keesc...@chromium.org> Signed-off-by: Mickaël Salaün <m...@digikod.net> Link: https://lore.kernel.org/r/20240301194037.532117-3-...@digikod.net --- Changes since v1: * Added 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
