4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland <mark.rutland@xxxxxxx> commit 7a7003b1da010d2b0d1dc8bf21c10f5c73b389f1 upstream. It's possible for a user to deliberately trigger __dump_instr with a chosen kernel address. Let's avoid problems resulting from this by using get_user() rather than __get_user(), ensuring that we don't erroneously access kernel memory. Where we use __dump_instr() on kernel text, we already switch to KERNEL_DS, so this shouldn't adversely affect those cases. Fixes: 60ffc30d5652810d ("arm64: Exception handling") Acked-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -116,7 +116,7 @@ static void __dump_instr(const char *lvl for (i = -4; i < 1; i++) { unsigned int val, bad; - bad = __get_user(val, &((u32 *)addr)[i]); + bad = get_user(val, &((u32 *)addr)[i]); if (!bad) p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);