e89aa81835
commit 78e7b15e17ac175e7eed9e21c6f92d03d3b0a6fa upstream.
The arch_teardown_msi_irqs() function assumes that controller ops
pointers were already checked in arch_setup_msi_irqs(), but this
assumption is wrong: arch_teardown_msi_irqs() can be called even when
arch_setup_msi_irqs() returns an error (-ENOSYS).
This can happen in the following scenario:
- msi_capability_init() calls pci_msi_setup_msi_irqs()
- pci_msi_setup_msi_irqs() returns -ENOSYS
- msi_capability_init() notices the error and calls free_msi_irqs()
- free_msi_irqs() calls pci_msi_teardown_msi_irqs()
This is easier to see when CONFIG_PCI_MSI_IRQ_DOMAIN is not set and
pci_msi_setup_msi_irqs() and pci_msi_teardown_msi_irqs() are just
aliases to arch_setup_msi_irqs() and arch_teardown_msi_irqs().
The call to free_msi_irqs() upon pci_msi_setup_msi_irqs() failure
seems legit, as it does additional cleanup; e.g.
list_del(&entry->list) and kfree(entry) inside free_msi_irqs() do
happen (MSI descriptors are allocated before pci_msi_setup_msi_irqs()
is called and need to be cleaned up if that fails).
Fixes: 6b2fd7efeb88 ("PCI/MSI/PPC: Remove arch_msi_check_device()")
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.