The patch titled Subject: memremap: check pfn validity before passing to pfn_to_page() has been removed from the -mm tree. Its filename was memremap-check-pfn-validity-before-passing-to-pfn_to_page.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Subject: memremap: check pfn validity before passing to pfn_to_page() In memremap's helper function try_ram_remap(), we dereference a struct page pointer that was derived from a PFN that is known to be covered by a 'System RAM' iomem region, and is thus assumed to be a 'valid' PFN, i.e., a PFN that has a struct page associated with it and is covered by the kernel direct mapping. However, the assumption that there is a 1:1 relation between the System RAM iomem region and the kernel direct mapping is not universally valid on all architectures, and on ARM and arm64, 'System RAM' may include regions for which pfn_valid() returns false. Generally speaking, both __va() and pfn_to_page() should only ever be called on PFNs/physical addresses for which pfn_valid() returns true, so add that check to try_ram_remap(). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/memremap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN kernel/memremap.c~memremap-check-pfn-validity-before-passing-to-pfn_to_page kernel/memremap.c --- a/kernel/memremap.c~memremap-check-pfn-validity-before-passing-to-pfn_to_page +++ a/kernel/memremap.c @@ -29,10 +29,10 @@ __weak void __iomem *ioremap_cache(resou static void *try_ram_remap(resource_size_t offset, size_t size) { - struct page *page = pfn_to_page(offset >> PAGE_SHIFT); + unsigned long pfn = PHYS_PFN(offset); /* In the simple case just return the existing linear address */ - if (!PageHighMem(page)) + if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn))) return __va(offset); return NULL; /* fallback to ioremap_cache */ } _ Patches currently in -mm which might be from ard.biesheuvel@xxxxxxxxxx are x86-kallsyms-disable-absolute-percpu-symbols-on-smp.patch x86-kallsyms-disable-absolute-percpu-symbols-on-smp-v5.patch kallsyms-dont-overload-absolute-symbol-type-for-percpu-symbols.patch kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table.patch kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table-v5.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html