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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Zhen Lei <thunder.leizhen@huawei.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.14 12/12] kobject: Add sanity check for kset->kobj.ktype in kset_register()
Date: Fri,  8 Sep 2023 20:41:15 -0400	[thread overview]
Message-ID: <20230909004115.3581195-12-sashal@kernel.org> (raw)
In-Reply-To: <20230909004115.3581195-1-sashal@kernel.org>

From: Zhen Lei <thunder.leizhen@huawei.com>

[ 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 <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20230805084114.1298-2-thunder.leizhen@huaweicloud.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 lib/kobject.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/kobject.c b/lib/kobject.c
index bbbb067de8ecd..b908655c58123 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -814,6 +814,11 @@ 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


      parent reply	other threads:[~2023-09-09  0:51 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-09  0:41 [PATCH AUTOSEL 4.14 01/12] media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 02/12] media: dw2102: Fix null-ptr-deref in dw2102_i2c_transfer() Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 03/12] media: af9005: Fix null-ptr-deref in af9005_i2c_xfer Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 04/12] media: anysee: fix null-ptr-deref in anysee_master_xfer Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 05/12] media: az6007: Fix null-ptr-deref in az6007_i2c_xfer() Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 06/12] iio: core: Use min() instead of min_t() to make code more robust Sasha Levin
2023-09-10 13:23   ` Jonathan Cameron
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 07/12] media: tuners: qt1010: replace BUG_ON with a regular error Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 08/12] media: pci: cx23885: replace BUG with error return Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 09/12] usb: gadget: fsl_qe_udc: validate endpoint index for ch9 udc Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 10/12] scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show() Sasha Levin
2023-09-09  0:41 ` [PATCH AUTOSEL 4.14 11/12] serial: cpm_uart: Avoid suspicious locking Sasha Levin
2023-09-09  0:41 ` Sasha Levin [this message]

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