From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6192C231C9C; Mon, 2 Jun 2025 14:30:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748874603; cv=none; b=Aer30nO/4zZDf5CAwM7/JJcmbqkU9aXcBMuvIGRR/UnmzSYULdEMuGKVIH74f5MCMjoukwNzyChNkX/ovPzjDXQNKQZ2stxsuAQwhhT5bgEgtxDA9mlCceSi3GyHqlOZWt0mCvCx/qHUaDyCR8REOFsV4fN5YmrlTDvduHFdKuk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748874603; c=relaxed/simple; bh=NmovvHZ83CDjL1Y90mr06epUCMlVzQNtTkfFnTGpf4c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DfpoNiHagINM0GzLC+jDGsFfsUcl2Cct7cfVIy+T3a0qXcaoY9N6AITjrihMZTFD7TktlCLGs74zvdrHBGb6UbAWSrM/k2pgfWJTXn6+F7Dx+qIk5FYME2SUjI9Oq1OkuacUlPsEOvnxJLo7X/R0h7VgR4KwNSFAWSPfErQ49BM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mFjrnro7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mFjrnro7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C60D7C4CEEB; Mon, 2 Jun 2025 14:30:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748874603; bh=NmovvHZ83CDjL1Y90mr06epUCMlVzQNtTkfFnTGpf4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mFjrnro7NLxvDWGRizSfAP2QbyOJ1aImt6w/0oL6NZuX1oZ5uKLsqYU5onB1BZ/qH FXK+i9yk96pH4pYogvLuyWVCM4GXYFEbOgh3V8bSNeVDKs98waAhNGQ36mQki8igEn ztRQqXfAkV+4UINxjRkLi389kqgREHeVJoRlqu50= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+7fb8a372e1f6add936dd@syzkaller.appspotmail.com, Petr Pavlu , Dmitry Antipov Subject: [PATCH 5.4 047/204] module: ensure that kobject_put() is safe for module type kobjects Date: Mon, 2 Jun 2025 15:46:20 +0200 Message-ID: <20250602134257.531970151@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134255.449974357@linuxfoundation.org> References: <20250602134255.449974357@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Antipov 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 Signed-off-by: Dmitry Antipov Link: https://lore.kernel.org/r/20250507065044.86529-1-dmantipov@yandex.ru Signed-off-by: Petr Pavlu Signed-off-by: Greg Kroah-Hartman --- kernel/params.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/kernel/params.c +++ b/kernel/params.c @@ -946,7 +946,9 @@ int module_sysfs_initialized; 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); } struct kobj_type module_ktype = {