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 D02871D7E5B; Mon, 12 May 2025 18:02:37 +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=1747072957; cv=none; b=V4u+KCmaL9AQOcX63hef9dnMqaRANlSVfJLgICk+25eFXERfIHmLucfSvrJtbhyavwimRJs63X18flph1Se3b/F3Hf0UI5txf1l9j9g8weTcLzj/s7zWgG/hdmOAZF8YQJZjWaVzY9cqyw5UuOi7N1/umtdjCmCaRtay9wggR5M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747072957; c=relaxed/simple; bh=jVtR00rDhofu3t5VmxcpbrOoG5K1hekQ+MlA3NBcVD4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pFwGaeLS3EDfGb4jHFC7/eShKVgV/Bdw7AZeuwmI6HoOMMGTdMcYCB8aGuuQu7O1yK32rLPPeJvRT4Lcy4kh6yCRAMqoOlMNtG09e4RKCoM3VS56sgr+F8kkxcte1BlSP2CsPeATzh02Wn+HDSyj10WHWfiXkCPp2zrCa3sQz8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NST3L6AZ; 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="NST3L6AZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C34D0C4CEE7; Mon, 12 May 2025 18:02:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1747072957; bh=jVtR00rDhofu3t5VmxcpbrOoG5K1hekQ+MlA3NBcVD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NST3L6AZcoPJj+0D5Zn7RoCMMO5BgEiQtIUTCEP2ZDh+NPfaWLSqTo+FB/nYHBa9F qZEPsA3sSp+uMEArNUI9PiTyOb9o6qq2/PkfNc3yIfVibaHnlUcdNbGX6YbOa9dRAP FBKmN89t0qzXp9XPfU90/pqC03K9uxnqnrtRWhRM= 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 6.12 110/184] module: ensure that kobject_put() is safe for module type kobjects Date: Mon, 12 May 2025 19:45:11 +0200 Message-ID: <20250512172046.308435565@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250512172041.624042835@linuxfoundation.org> References: <20250512172041.624042835@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 6.12-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 @@ -949,7 +949,9 @@ 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 = {