Commit d1f5a77f authored Aug 08, 2007 by Benjamin Herrenschmidt Committed by Paul Mackerras Aug 10, 2007

[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 <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

parent 8f2ea1fd

arch/powerpc/mm/slice.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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))

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