diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2016-01-05 20:32:47 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2016-01-07 12:17:39 -0500 |
| commit | 049fb9bd416077b3622d317a45796be4f2431df3 (patch) | |
| tree | 407e360324e0370e8a4e73e15de76959e6ea1f24 | |
| parent | f36d1be2930ede0a1947686e1126ffda5d5ee1bb (diff) | |
ftrace/module: Call clean up function when module init fails early
If the module init code fails after calling ftrace_module_init() and before
calling do_init_module(), we can suffer from a memory leak. This is because
ftrace_module_init() allocates pages to store the locations that ftrace
hooks are placed in the module text. If do_init_module() fails, it still
calls the MODULE_GOING notifiers which will tell ftrace to do a clean up of
the pages it allocated for the module. But if load_module() fails before
then, the pages allocated by ftrace_module_init() will never be freed.
Call ftrace_release_mod() on the module if load_module() fails before
getting to do_init_module().
Link: http://lkml.kernel.org/r/567CEA31.1070507@intel.com
Reported-by: "Qiu, PeiyangX" <peiyangx.qiu@intel.com>
Fixes: a949ae560a511 "ftrace/module: Hardcode ftrace_module_init() call into load_module()"
Cc: stable@vger.kernel.org # v2.6.38+
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | include/linux/ftrace.h | 1 | ||||
| -rw-r--r-- | kernel/module.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index eae6548efbf0..60048c50404e 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -586,6 +586,7 @@ extern int ftrace_arch_read_dyn_info(char *buf, int size); extern int skip_trace(unsigned long ip); extern void ftrace_module_init(struct module *mod); +extern void ftrace_release_mod(struct module *mod); extern void ftrace_disable_daemon(void); extern void ftrace_enable_daemon(void); diff --git a/kernel/module.c b/kernel/module.c index 8f051a106676..38c7bd5583ff 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3571,6 +3571,12 @@ static int load_module(struct load_info *info, const char __user *uargs, synchronize_sched(); mutex_unlock(&module_mutex); free_module: + /* + * Ftrace needs to clean up what it initialized. + * This does nothing if ftrace_module_init() wasn't called, + * but it must be called outside of module_mutex. + */ + ftrace_release_mod(mod); /* Free lock-classes; relies on the preceding sync_rcu() */ lockdep_free_key_range(mod->module_core, mod->core_size); |