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.
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Fixes: 60ffc30d5652810d ("arm64: Exception handling")
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
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);
--
2.11.0