Reject specialized load instructions so a bytecode crafted with
nefarious intent cannot:
- Read user-space memory without proper get_user accessors,
- Read a memory area larger than the memory targeted by the instrumentation.
This prevents bytecode received from a tracing group user from oopsing
the kernel or disclosing the content of kernel memory to the tracing
group.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ia70bb2da645d6a0b36515a8ac51995c13283d4cc
dbg_printk("Validate load field\n");
break;
}
dbg_printk("Validate load field\n");
break;
}
+
+ /*
+ * Disallow already specialized bytecode op load field instructions to
+ * ensure that the received bytecode does not:
+ *
+ * - Read user-space memory without proper get_user accessors,
+ * - Read a memory area larger than the memory targeted by the instrumentation.
+ */
case FILTER_OP_LOAD_FIELD_S8:
case FILTER_OP_LOAD_FIELD_S8:
- {
- dbg_printk("Validate load field s8\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_S16:
case FILTER_OP_LOAD_FIELD_S16:
- {
- dbg_printk("Validate load field s16\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_S32:
case FILTER_OP_LOAD_FIELD_S32:
- {
- dbg_printk("Validate load field s32\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_S64:
case FILTER_OP_LOAD_FIELD_S64:
- {
- dbg_printk("Validate load field s64\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_U8:
case FILTER_OP_LOAD_FIELD_U8:
- {
- dbg_printk("Validate load field u8\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_U16:
case FILTER_OP_LOAD_FIELD_U16:
- {
- dbg_printk("Validate load field u16\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_U32:
case FILTER_OP_LOAD_FIELD_U32:
- {
- dbg_printk("Validate load field u32\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_U64:
case FILTER_OP_LOAD_FIELD_U64:
- {
- dbg_printk("Validate load field u64\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_STRING:
case FILTER_OP_LOAD_FIELD_STRING:
- {
- dbg_printk("Validate load field string\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_SEQUENCE:
case FILTER_OP_LOAD_FIELD_SEQUENCE:
- {
- dbg_printk("Validate load field sequence\n");
- break;
- }
case FILTER_OP_LOAD_FIELD_DOUBLE:
{
case FILTER_OP_LOAD_FIELD_DOUBLE:
{
- dbg_printk("Validate load field double\n");
- break;
+ dbg_printk("Validate load field, reject specialized load instruction (%d)\n",
+ (int) opcode);
+ ret = -EINVAL;
+ goto end;
}
case FILTER_OP_GET_SYMBOL:
}
case FILTER_OP_GET_SYMBOL: