diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2016-01-05 20:32:47 -0500 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2016-01-25 10:44:04 +0000 |
| commit | fdc08799e6ee104d6ed0bab706997a97059e15c7 (patch) | |
| tree | eb7b21bed171e1464c853deb57798ddfd5cb6e52 /kernel | |
| parent | 81e6eb85cba718114d848eea83fe4e9490ed6e2e (diff) | |
ftrace/module: Call clean up function when module init fails early
commit 049fb9bd416077b3622d317a45796be4f2431df3 upstream.
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()"
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/module.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c index ed4d3b7ec58a..365b0a9d87b3 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3339,6 +3339,12 @@ static int load_module(struct load_info *info, const char __user *uargs, wake_up_all(&module_wq); 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); module_deallocate(mod, info); free_copy: free_copy(info); |