From: Anshuman Khandual <anshuman.khandual@xxxxxxx> Subject: mm/ioremap: check virtual address alignment while creating huge mappings Virtual address alignment is essential in ensuring correct clearing for all intermediate level pgtable entries and freeing associated pgtable pages. An unaligned address can end up randomly freeing pgtable page that potentially still contains valid mappings. Hence also check it's alignment along with existing phys_addr check. Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Toshi Kani <toshi.kani@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Chintan Pandya <cpandya@xxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/ioremap.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/lib/ioremap.c~mm-ioremap-check-virtual-address-alignment-while-creating-huge-mappings +++ a/lib/ioremap.c @@ -86,6 +86,9 @@ static int ioremap_try_huge_pmd(pmd_t *p if ((end - addr) != PMD_SIZE) return 0; + if (!IS_ALIGNED(addr, PMD_SIZE)) + return 0; + if (!IS_ALIGNED(phys_addr, PMD_SIZE)) return 0; @@ -126,6 +129,9 @@ static int ioremap_try_huge_pud(pud_t *p if ((end - addr) != PUD_SIZE) return 0; + if (!IS_ALIGNED(addr, PUD_SIZE)) + return 0; + if (!IS_ALIGNED(phys_addr, PUD_SIZE)) return 0; @@ -166,6 +172,9 @@ static int ioremap_try_huge_p4d(p4d_t *p if ((end - addr) != P4D_SIZE) return 0; + if (!IS_ALIGNED(addr, P4D_SIZE)) + return 0; + if (!IS_ALIGNED(phys_addr, P4D_SIZE)) return 0; _
