Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues: - [High] Missing IS_ERR() check on kthread_run() leads to kernel panic on module unload -- commit 83cdbb346a20d7607e5ef97af8d7a9a9c9c57687 Author: Haotian Zhang <[email protected]> samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify This commit fixes a bug in the ftrace-direct-modify sample module where the return value of kthread_run() was not checked with IS_ERR(). Without this check, an initialization failure could leave an error pointer in simple_tsk, causing a kernel panic when kthread_stop() is called during module unload. The patch correctly propagates the error and cleans up by unregistering the ftrace direct call on failure. > diff --git a/samples/ftrace/ftrace-direct-modify.c > b/samples/ftrace/ftrace-direct-modify.c > index 1ba1927b548ee..164d9dd6fd921 100644 > --- a/samples/ftrace/ftrace-direct-modify.c > +++ b/samples/ftrace/ftrace-direct-modify.c > @@ -320,9 +320,15 @@ static int __init ftrace_direct_init(void) > ftrace_set_filter_ip(&direct, (unsigned long) my_ip, 0, 0); > 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; > } [Severity: High] This is a pre-existing issue, but it looks like the exact same missing IS_ERR() check is present in samples/ftrace/ftrace-direct-multi-modify.c: samples/ftrace/ftrace-direct-multi-modify.c:ftrace_direct_multi_init() { [ ... ] ret = register_ftrace_direct(&direct, my_tramp); if (!ret) simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn"); return ret; } If kthread_run() fails here, it returns an ERR_PTR which is assigned to simple_tsk, and the module still successfully loads since the function returns 0. When the module is unloaded, kthread_stop() is called on the ERR_PTR, which dereferences it and causes a kernel panic. Should this same fix be applied to ftrace_direct_multi_init() in ftrace-direct-multi-modify.c as well? -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=1
