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")
Acked-by: Will Deacon <>
Signed-off-by: Mark Rutland <>
Signed-off-by: Catalin Marinas <>
1 file changed