c1114090ce
commit a2e7e59a94269484a83386972ca07c22fd188854 upstream. It turns out there are more subtle races beyond just the main part of __iommu_probe_device() itself running in parallel - the dev_iommu_free() on the way out of an unsuccessful probe can still manage to trip up concurrent accesses to a device's fwspec. Thus, extend the scope of iommu_probe_device_lock() to also serialise fwspec creation and initial retrieval. Reported-by: Zhenhua Huang <quic_zhenhuah@quicinc.com> Link: https://lore.kernel.org/linux-iommu/e2e20e1c-6450-4ac5-9804-b0000acdf7de@quicinc.com/ Fixes: 01657bc14a39 ("iommu: Avoid races around device probe") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: André Draszik <andre.draszik@linaro.org> Tested-by: André Draszik <andre.draszik@linaro.org> Link: https://lore.kernel.org/r/16f433658661d7cadfea51e7c65da95826112a2b.1700071477.git.robin.murphy@arm.com Cc: stable@vger.kernel.org Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.