Commit 50bad62b authored Sep 21, 2016 by Laura Abbott Committed by Sami Tolvanen Oct 05, 2016

BACKPORT: arm64: Correctly bounds check virt_addr_valid



virt_addr_valid is supposed to return true if and only if virt_to_page
returns a valid page structure. The current macro does math on whatever
address is given and passes that to pfn_valid to verify. vmalloc and
module addresses can happen to generate a pfn that 'happens' to be
valid. Fix this by only performing the pfn_valid check on addresses that
have the potential to be valid.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Bug: 31374226
Change-Id: I75cbeb3edb059f19af992b7f5d0baa283f95991b
(cherry picked from commit ca219452c6b8a6cd1369b6a78b1cf069d0386865)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

parent 1a6c07cf

arch/arm64/include/asm/memory.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -193,7 +193,11 @@ static inline void *phys_to_virt(phys_addr_t x)
		#define ARCH_PFN_OFFSET ((unsigned long)PHYS_PFN_OFFSET)

		#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
		#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
		#define _virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)

		#define _virt_addr_is_linear(kaddr) (((u64)(kaddr)) >= PAGE_OFFSET)
		#define virt_addr_valid(kaddr) (_virt_addr_is_linear(kaddr) && \
		_virt_addr_valid(kaddr))

		#endif