From: Greg KH <gregkh@linuxfoundation.org>
To: Yang Yingliang <yangyingliang@huawei.com>
Cc: tglx@linutronix.de, kraig@google.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] genirq/irqdesc: fix WARNING in irq_sysfs_del()
Date: Mon, 28 Nov 2022 12:42:17 +0100 [thread overview]
Message-ID: <Y4Semf3t/hgPsr3v@kroah.com> (raw)
In-Reply-To: <20221126082716.438271-1-yangyingliang@huawei.com>
On Sat, Nov 26, 2022 at 04:27:16PM +0800, Yang Yingliang wrote:
> I got the lots of WARNING report when doing fault injection test:
>
> kernfs: can not remove 'chip_name', no directory
> WARNING: CPU: 0 PID: 253 at fs/kernfs/dir.c:1616 kernfs_remove_by_name_ns+0xce/0xe0
> RIP: 0010:kernfs_remove_by_name_ns+0xce/0xe0
> Call Trace:
> <TASK>
> remove_files.isra.1+0x3f/0xb0
> sysfs_remove_group+0x68/0xe0
> sysfs_remove_groups+0x41/0x70
> __kobject_del+0x45/0xc0
> kobject_del+0x29/0x40
> free_desc+0x42/0x70
> irq_free_descs+0x5e/0x90
>
> kernfs: can not remove 'hwirq', no directory
> WARNING: CPU: 0 PID: 253 at fs/kernfs/dir.c:1616 kernfs_remove_by_name_ns+0xce/0xe0
> RIP: 0010:kernfs_remove_by_name_ns+0xce/0xe0
> Call Trace:
> <TASK>
> remove_files.isra.1+0x3f/0xb0
> sysfs_remove_group+0x68/0xe0
> sysfs_remove_groups+0x41/0x70
> __kobject_del+0x45/0xc0
> kobject_del+0x29/0x40
> free_desc+0x42/0x70
> irq_free_descs+0x5e/0x90
>
> If irq_sysfs_add() fails in alloc_descs(), the directory of interrupt
> informations is not added to sysfs, it causes the WARNINGs when removing
> the information files. Fix this by adding check kobj.state_in_sysfs in
> irq_sysfs_del().
>
> Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
> kernel/irq/irqdesc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
> index a91f9001103c..e391f4195b87 100644
> --- a/kernel/irq/irqdesc.c
> +++ b/kernel/irq/irqdesc.c
> @@ -303,7 +303,7 @@ static void irq_sysfs_del(struct irq_desc *desc)
> * kobject_del() complains about a object with no parent, so make
> * it conditional.
> */
> - if (irq_kobj_base)
> + if (irq_kobj_base && desc->kobj.state_in_sysfs)
No, this is not ok, you are poking around in the core of sysfs in a
field that should be private and not be able to be seen by anyone else.
Fix this properly and do not try to remove a kobject that you know was
not registered properly.
thanks,
greg k-h
prev parent reply other threads:[~2022-11-28 11:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-26 8:27 [PATCH] genirq/irqdesc: fix WARNING in irq_sysfs_del() Yang Yingliang
2022-11-28 11:42 ` Greg KH [this message]
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