diff options
| author | Haotian Zhang <vulab@iscas.ac.cn> | 2026-08-26 09:50:50 +0800 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-08-26 15:50:22 -0400 |
| commit | 6727b7618f49401acf373fa3ec5712e2ec52e5cf (patch) | |
| tree | 9ad45d1dab6f6a0768882b210b1e364802d83c13 | |
| parent | d79fb758e7e2e7a181eab630c0545a56041c473d (diff) | |
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
ftrace_direct_multi_init() assigns kthread_run()'s return value to
simple_tsk without an IS_ERR() check. When kthread_run() fails it
returns ERR_PTR(-ENOMEM), but init still returns 0, so the module loads
with simple_tsk holding an error pointer. On unload,
ftrace_direct_multi_exit() then passes that ERR_PTR to kthread_stop(),
leading to a null-pointer-dereference.
Check the return value of kthread_run() with IS_ERR(); on failure,
unregister the ftrace direct call and propagate the error code.
Link: https://patch.msgid.link/20260826015050.10772-1-vulab@iscas.ac.cn
Fixes: e1067a07cfbc ("ftrace/samples: Add module to test multi direct modify interface")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | samples/ftrace/ftrace-direct-multi-modify.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c index 7a7822dfeb50..b03766c6217b 100644 --- a/samples/ftrace/ftrace-direct-multi-modify.c +++ b/samples/ftrace/ftrace-direct-multi-modify.c @@ -364,9 +364,15 @@ static int __init ftrace_direct_multi_init(void) ret = register_ftrace_direct(&direct, my_tramp); - if (!ret) - simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn"); - return ret; + if (ret) + return ret; + simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn"); + if (IS_ERR(simple_tsk)) { + unregister_ftrace_direct(&direct, my_tramp, true); + return PTR_ERR(simple_tsk); + } + + return 0; } static void __exit ftrace_direct_multi_exit(void) |