diff mbox series

[Stable-7.2.14,07/40] target/i386: do not crash if microvm guest uses SGX CPUID leaves

Message ID 20240906051633.10288-7-mjt@tls.msk.ru (mailing list archive)
State New, archived
Headers show
Series Patch Round-up for stable 7.2.14, freeze on 2024-09-16 | expand

Commit Message

Michael Tokarev Sept. 6, 2024, 5:15 a.m. UTC 
From: Paolo Bonzini <pbonzini@redhat.com>

sgx_epc_get_section assumes a PC platform is in use:

bool sgx_epc_get_section(int section_nr, uint64_t *addr, uint64_t *size)
{
    PCMachineState *pcms = PC_MACHINE(qdev_get_machine());

However, sgx_epc_get_section is called by CPUID regardless of whether
SGX state has been initialized or which platform is in use.  Check
whether the machine has the right QOM class and if not behave as if
there are no EPC sections.

Fixes: 1dec2e1f19f ("i386: Update SGX CPUID info according to hardware/KVM/user input", 2021-09-30)
Cc: qemu-stable@nongnu.org
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2142
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 13be929aff804581b21e69087a9caf3698fd5c3c)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff mbox series

Patch

diff --git a/hw/i386/sgx.c b/hw/i386/sgx.c
index 09d9c7c73d..f64987c6dd 100644
--- a/hw/i386/sgx.c
+++ b/hw/i386/sgx.c
@@ -268,10 +268,12 @@  void hmp_info_sgx(Monitor *mon, const QDict *qdict)
 
 bool sgx_epc_get_section(int section_nr, uint64_t *addr, uint64_t *size)
 {
-    PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
+    PCMachineState *pcms =
+        (PCMachineState *)object_dynamic_cast(qdev_get_machine(),
+                                              TYPE_PC_MACHINE);
     SGXEPCDevice *epc;
 
-    if (pcms->sgx_epc.size == 0 || pcms->sgx_epc.nr_sections <= section_nr) {
+    if (!pcms || pcms->sgx_epc.size == 0 || pcms->sgx_epc.nr_sections <= section_nr) {
         return true;
     }