linux-kernel - Re: [PATCH v2] PCI: vmd: Fix wrong kfree() in vmd_msi

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87bjorxc22.fsf@yellow.woof>
Date: Thu, 07 Aug 2025 19:43:17 +0200
From: Nam Cao <namcao@...utronix.de>
To: Bjorn Helgaas <helgaas@...nel.org>
Cc: Nirmal Patel <nirmal.patel@...ux.intel.com>, Jonathan Derrick
 <jonathan.derrick@...ux.dev>, Lorenzo Pieralisi <lpieralisi@...nel.org>,
 Krzysztof Wilczyński <kwilczynski@...nel.org>, Manivannan
 Sadhasivam
 <mani@...nel.org>, Rob Herring <robh@...nel.org>, Bjorn Helgaas
 <bhelgaas@...gle.com>, Thomas Gleixner <tglx@...utronix.de>,
 linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org, Kenneth Crudup
 <kenny@...ix.com>, Ammar Faizi <ammarfaizi2@...weeb.org>
Subject: Re: [PATCH v2] PCI: vmd: Fix wrong kfree() in vmd_msi_free()

Bjorn Helgaas <helgaas@...nel.org> writes:
> On Thu, Aug 07, 2025 at 10:10:51AM +0200, Nam Cao wrote:
>> vmd_msi_alloc() allocates struct vmd_irq and stashes it into
>> irq_data->chip_data associated with the VMD's interrupt domain.
>> vmd_msi_free() extracts the pointer by calling irq_get_chip_data() and
>> frees it.
>> 
>> irq_get_chip_data() returns the chip_data associated with the top interrupt
>> domain. This worked in the past, because VMD's interrupt domain was the top
>> domain.
>> 
>> But since commit d7d8ab87e3e7 ("PCI: vmd: Switch to
>> msi_create_parent_irq_domain()") changed the interrupt domain hierarchy,
>> VMD's interrupt domain is not the top domain anymore. irq_get_chip_data()
>> now returns the chip_data at the MSI devices' interrupt domains. It is
>> therefore broken for vmd_msi_free() to kfree() this chip_data.
>> 
>> Fix this issue, correctly extract the chip_data associated with the VMD's
>> interrupt domain.
...
>
> Applied to pci/for-linus for v6.17, thanks!
>
> I assume you checked the other msi_create_parent_irq_domain() changes
> for similar problems?

Not before you reminded me :(

But yes, none of the similar PCI patches has the same problem.

Nam