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 5CFF930FA4 for ; Wed, 20 Sep 2023 12:20:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D72F3C433C8; Wed, 20 Sep 2023 12:20:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695212435; bh=wwOCfvfufn799fXeXCXzRzer9tySBC1TgSL7+rnCHtw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xdeAO9JeI5wMj9IwFCGaxRxo/RvqnMa4NTBJ8MH9d+O85aw65pn/6AsJ82CPVlYVg bPPxHEqciSnFgIygTPTrYcPY80DS/mDpUWN9wTOiq0hYsV88dXtWj4U3X88d3Rse+W OzLtTIVDJuz7oRNLQAakksXrlToPHCPpAKU3S2bo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhen Lei , Sasha Levin Subject: [PATCH 4.19 266/273] kobject: Add sanity check for kset->kobj.ktype in kset_register() Date: Wed, 20 Sep 2023 13:31:46 +0200 Message-ID: <20230920112854.452562159@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112846.440597133@linuxfoundation.org> References: <20230920112846.440597133@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhen Lei [ Upstream commit 4d0fe8c52bb3029d83e323c961221156ab98680b ] When I register a kset in the following way: static struct kset my_kset; kobject_set_name(&my_kset.kobj, "my_kset"); ret = kset_register(&my_kset); A null pointer dereference exception is occurred: [ 4453.568337] Unable to handle kernel NULL pointer dereference at \ virtual address 0000000000000028 ... ... [ 4453.810361] Call trace: [ 4453.813062] kobject_get_ownership+0xc/0x34 [ 4453.817493] kobject_add_internal+0x98/0x274 [ 4453.822005] kset_register+0x5c/0xb4 [ 4453.825820] my_kobj_init+0x44/0x1000 [my_kset] ... ... Because I didn't initialize my_kset.kobj.ktype. According to the description in Documentation/core-api/kobject.rst: - A ktype is the type of object that embeds a kobject. Every structure that embeds a kobject needs a corresponding ktype. So add sanity check to make sure kset->kobj.ktype is not NULL. Signed-off-by: Zhen Lei Link: https://lore.kernel.org/r/20230805084114.1298-2-thunder.leizhen@huaweicloud.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- lib/kobject.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/lib/kobject.c b/lib/kobject.c index 97d86dc17c42b..2bab65232925a 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -829,6 +829,11 @@ int kset_register(struct kset *k) if (!k) return -EINVAL; + if (!k->kobj.ktype) { + pr_err("must have a ktype to be initialized properly!\n"); + return -EINVAL; + } + kset_init(k); err = kobject_add_internal(&k->kobj); if (err) -- 2.40.1