This is a note to let you know that I've just added the patch titled
kobject: Add sanity check for kset->kobj.ktype in kset_register()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kobject-add-sanity-check-for-kset-kobj.ktype-in-kset.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1332a1761eea8a5fd0a62101b2a39e8718ce7575
Author: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Date: Sat Aug 5 16:41:13 2023 +0800
kobject: Add sanity check for kset->kobj.ktype in kset_register()
[ 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@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230805084114.1298-2-thunder.leizhen@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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)
