forked from Minki/linux
07b742a4d9
When the kernel is built with KASAN_GENERIC or KASAN_SW_TAGS, shadow memory is allocated and mapped for all legitimate kernel addresses, and prior to a regular memory access instrumentation will read from the corresponding shadow address. Due to the way memory addresses are converted to shadow addresses, bogus pointers (e.g. NULL) can generate shadow addresses out of the bounds of allocated shadow memory. For example, with KASAN_GENERIC and 48-bit VAs, NULL would have a shadow address of dfff800000000000, which falls between the TTBR ranges. To make such cases easier to debug, this patch makes die_kernel_fault() dump the real memory address range for any potential KASAN shadow access using kasan_non_canonical_hook(), which results in fault information as below when KASAN is enabled: | Unable to handle kernel paging request at virtual address dfff800000000017 | KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf] | Mem abort info: | ESR = 0x96000004 | EC = 0x25: DABT (current EL), IL = 32 bits | SET = 0, FnV = 0 | EA = 0, S1PTW = 0 | FSC = 0x04: level 0 translation fault | Data abort info: | ISV = 0, ISS = 0x00000004 | CM = 0, WnR = 0 | [dfff800000000017] address between user and kernel address ranges Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will@kernel.org> Tested-by: Andrey Konovalov <andreyknvl@gmail.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20211207183226.834557-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> |
||
|---|---|---|
| .. | ||
| alpha | ||
| arc | ||
| arm | ||
| arm64 | ||
| csky | ||
| h8300 | ||
| hexagon | ||
| ia64 | ||
| m68k | ||
| microblaze | ||
| mips | ||
| nds32 | ||
| nios2 | ||
| openrisc | ||
| parisc | ||
| powerpc | ||
| riscv | ||
| s390 | ||
| sh | ||
| sparc | ||
| um | ||
| x86 | ||
| xtensa | ||
| .gitignore | ||
| Kconfig | ||