From: Dmitry Antipov <dmantipov@yandex.ru> stable inclusion from stable-v6.6.91 commit faa9059631d3491d699c69ecf512de9e1a3d6649 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICBIZQ CVE: CVE-2025-37995 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit a6aeb739974ec73e5217c75a7c008a688d3d5cf1 upstream. In 'lookup_or_create_module_kobject()', an internal kobject is created using 'module_ktype'. So call to 'kobject_put()' on error handling path causes an attempt to use an uninitialized completion pointer in 'module_kobject_release()'. In this scenario, we just want to release kobject without an extra synchronization required for a regular module unloading process, so adding an extra check whether 'complete()' is actually required makes 'kobject_put()' safe. Reported-by: syzbot+7fb8a372e1f6add936dd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7fb8a372e1f6add936dd Fixes: 942e443127e9 ("module: Fix mod->mkobj.kobj potentially freed too early") Cc: stable@vger.kernel.org Suggested-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Link: https://lore.kernel.org/r/20250507065044.86529-1-dmantipov@yandex.ru Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Pan Taixi <pantaixi1@huawei.com> --- kernel/params.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/params.c b/kernel/params.c index c7aed3c51cd538..e39ac5420cd6dc 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -945,7 +945,9 @@ struct kset *module_kset; static void module_kobj_release(struct kobject *kobj) { struct module_kobject *mk = to_module_kobject(kobj); - complete(mk->kobj_completion); + + if (mk->kobj_completion) + complete(mk->kobj_completion); } const struct kobj_type module_ktype = { -- cgit 1.2.3-korg