| From 7a7003b1da010d2b0d1dc8bf21c10f5c73b389f1 Mon Sep 17 00:00:00 2001 |
| From: Mark Rutland <mark.rutland@arm.com> |
| Date: Thu, 2 Nov 2017 16:12:03 +0000 |
| Subject: arm64: ensure __dump_instr() checks addr_limit |
| |
| From: Mark Rutland <mark.rutland@arm.com> |
| |
| 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@arm.com> |
| Signed-off-by: Mark Rutland <mark.rutland@arm.com> |
| Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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 |
| @@ -112,7 +112,7 @@ 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); |