3.13.11-ckt33 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx> 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@xxxxxxxxx Reported-by: "Qiu, PeiyangX" <peiyangx.qiu@xxxxxxxxx> Fixes: a949ae560a511 "ftrace/module: Hardcode ftrace_module_init() call into load_module()" Acked-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx> Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx> --- include/linux/ftrace.h | 1 + kernel/module.c | 6 ++++++ 2 files changed, 7 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 20e5093..18e906a 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -525,6 +525,7 @@ 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 49f17c2..16af9a9 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3317,6 +3317,12 @@ 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); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html