mi: verify length of data before reading header

The total length could be shorter than then the header. Thus check
first the message length.

Running test mi_aem_ep_based_failure_conditions...==3181== Conditional jump or move depends on uninitialised value(s)
==3181==    at 0x486E7D7: validate_enabled_list (mi.c:1445)
==3181==    by 0x486E7D7: nvme_mi_aem_get_enabled (mi.c:1730)
==3181==    by 0x486E8F3: aem_disable_enabled (mi.c:1605)
==3181==    by 0x486EB3A: nvme_mi_aem_enable (mi.c:1667)
==3181==    by 0x401621: test_mi_aem_ep_based_failure_helper (mi-mctp.c:1187)
==3181==    by 0x401688: test_mi_aem_ep_based_failure_conditions (mi-mctp.c:1204)
==3181==    by 0x400FF2: run_test (mi-mctp.c:1448)
==3181==    by 0x400FF2: main (mi-mctp.c:1472)

Signed-off-by: Daniel Wagner <[email protected]>

Author: igaw

libnvme/src/nvme/mi.c

@@ -1440,6 +1440,8 @@ void nvme_mi_aem_aeolli_set_aeoltl(struct nvme_mi_aem_occ_list_hdr *hdr, __u32 a
 
 static int validate_enabled_list(struct nvme_mi_aem_supported_list *list, size_t len)
 {
+	if (len < sizeof(struct nvme_mi_aem_supported_list))
+		return -EPROTO;
 	if (list->hdr.aeslver != 0)
 		return -EPROTO;
 	if (list->hdr.aeslhl != sizeof(struct nvme_mi_aem_supported_list))