From 7a7003b1da010d2b0d1dc8bf21c10f5c73b389f1 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 2 Nov 2017 16:12:03 +0000 Subject: arm64: ensure __dump_instr() checks addr_limit 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") Cc: stable@vger.kernel.org Acked-by: Will Deacon Signed-off-by: Mark Rutland Signed-off-by: Catalin Marinas --- arch/arm64/kernel/traps.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 5ea4b85aee0e..8383af15a759 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -118,7 +118,7 @@ static void __dump_instr(const char *lvl, struct pt_regs *regs) 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); -- cgit v1.2.3