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 <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 5ea4b85..8383af1 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -118,7 +118,7 @@
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);
