From d1f5a77f2c9db5b8a565eabdf8b534b02e32cc44 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 8 Aug 2007 15:44:15 +1000 Subject: [PATCH] [POWERPC] Fix size check for hugetlbfs My "slices" address space management code that was added in the 2.6.22 implementation of get_unmapped_area() doesn't properly check that the size is a multiple of the requested page size. This allows userland to create VMAs that aren't a multiple of the huge page size with hugetlbfs (since hugetlbfs entirely relies on get_unmapped_area() to do that checking) which leads to a kernel BUG() when such areas are torn down. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras --- arch/powerpc/mm/slice.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c index f833dba2a028..d5fd3909d13a 100644 --- a/arch/powerpc/mm/slice.c +++ b/arch/powerpc/mm/slice.c @@ -405,6 +405,8 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len, if (len > mm->task_size) return -ENOMEM; + if (len & ((1ul << pshift) - 1)) + return -EINVAL; if (fixed && (addr & ((1ul << pshift) - 1))) return -EINVAL; if (fixed && addr > (mm->task_size - len)) -- 2.20.1