From: Benjamin Herrenschmidt Date: Wed, 8 Aug 2007 05:44:15 +0000 (+1000) Subject: powerpc: Fix size check for hugetlbfs X-Git-Tag: v2.6.22.3~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=51a718fdf27c4bf61936f146516b9f623b4e9875;p=thirdparty%2Fkernel%2Fstable.git powerpc: Fix size check for hugetlbfs My "slices" address space management code that was added in 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/powerpc/mm/slice.c b/arch/powerpc/mm/slice.c index f833dba2a0287..d5fd3909d13a2 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))