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[ Upstream commit 29859aeb8a6ea17ba207933a81b6b77b4d4df81a ] When run on a 64-bit system in selftest, the v7s driver may obtain page table with physical addresses larger than 32-bit. Level-2 tables are 1KB and are are allocated with slab, which doesn't accept the GFP_DMA32 flag. Currently map() truncates the address written in the PTE, causing iova_to_phys() or unmap() to access invalid memory. Kasan reports it as a use-after-free. To avoid any nasty surprise, test if the physical address fits in a PTE before returning a new table. 32-bit systems, which are the main users of this page table format, shouldn't see any difference. Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> 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.