From 6b95ab4218bfa59bc315105127ffe03aef3b5742 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual <anshuman.khandual@arm.com> Date: Tue, 16 Jul 2019 16:27:30 -0700 Subject: [PATCH] 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@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- lib/ioremap.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/ioremap.c b/lib/ioremap.c index 063213685563c..a95161d9c883c 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -86,6 +86,9 @@ static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr, 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 *pud, unsigned long addr, 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 *p4d, unsigned long addr, if ((end - addr) != P4D_SIZE) return 0; + if (!IS_ALIGNED(addr, P4D_SIZE)) + return 0; + if (!IS_ALIGNED(phys_addr, P4D_SIZE)) return 0; -- GitLab