From 970970dcb4fca4fdcbb1b9bf4d7cd686796dc9d6 Mon Sep 17 00:00:00 2001 From: Grazvydas Ignotas Date: Thu, 12 Feb 2015 15:00:19 -0800 Subject: mm/memory.c: actually remap enough memory commit 9cb12d7b4ccaa976f97ce0c5fd0f1b6a83bc2a75 upstream. For whatever reason, generic_access_phys() only remaps one page, but actually allows to access arbitrary size. It's quite easy to trigger large reads, like printing out large structure with gdb, which leads to a crash. Fix it by remapping correct size. Fixes: 28b2ee20c7cb ("access_process_vm device memory infrastructure") Signed-off-by: Grazvydas Ignotas Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index db2916f5f378..cf05415c25a6 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4079,7 +4079,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, if (follow_phys(vma, addr, write, &prot, &phys_addr)) return -EINVAL; - maddr = ioremap_prot(phys_addr, PAGE_SIZE, prot); + maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot); if (write) memcpy_toio(maddr + offset, buf, len); else -- cgit v1.2.3