Currently, the __is_lm_address() check just masks out the top 12 bits of the address, but if they are 0, it still yields a true result. This has as a side effect that virt_addr_valid() returns true even for invalid virtual addresses (e.g. 0x0).
Fix the detection checking that it's actually a kernel address starting at PAGE_OFFSET. Fixes: f4693c2716b35 ("arm64: mm: extend linear region for 52-bit VA configurations") Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Will Deacon <w...@kernel.org> Suggested-by: Catalin Marinas <catalin.mari...@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frasc...@arm.com> --- arch/arm64/include/asm/memory.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 18fce223b67b..e04ac898ffe4 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -249,7 +249,7 @@ static inline const void *__tag_set(const void *addr, u8 tag) /* * The linear kernel range starts at the bottom of the virtual address space. */ -#define __is_lm_address(addr) (((u64)(addr) & ~PAGE_OFFSET) < (PAGE_END - PAGE_OFFSET)) +#define __is_lm_address(addr) (((u64)(addr) ^ PAGE_OFFSET) < (PAGE_END - PAGE_OFFSET)) #define __lm_to_phys(addr) (((addr) & ~PAGE_OFFSET) + PHYS_OFFSET) #define __kimg_to_phys(addr) ((addr) - kimage_voffset) -- 2.30.0