Re: [PATCH] qemu: segmentation fault in virtqemud executing qemuDomainUndefineFlags

Jim Fehlig <jfehlig@xxxxxxxx> · Tue, 1 Mar 2022 16:21:38 -0700

On 3/1/22 10:47, Boris Fiuczynski wrote:
Commit 5adfb3472342741c443ac91dee0abb18b5a3d038 causes a segmentation fault.

Stack trace of thread 664419:
  #0  0x000003ff62ec553c in qemuDomainUndefineFlags (dom=0x3ff6c002810, flags=<optimized out>) at ../src/qemu/qemu_driver.c:6618
  #1  0x000003ff876a7e5c in virDomainUndefineFlags (domain=domain@entry=0x3ff6c002810, flags=<optimized out>) at ../src/libvirt-domain.c:6519
  #2  0x000002aa2b64a808 in remoteDispatchDomainUndefineFlags (server=0x2aa2c3d7880, msg=0x2aa2c3d2770, args=<optimized out>, rerr=0x3ff8287b950, client=<optimized out>)
         at src/remote/remote_daemon_dispatch_stubs.h:13080
  #3  remoteDispatchDomainUndefineFlagsHelper (server=0x2aa2c3d7880, client=<optimized out>, msg=0x2aa2c3d2770, rerr=0x3ff8287b950, args=<optimized out>, ret=0x0)
         at src/remote/remote_daemon_dispatch_stubs.h:13059
  #4  0x000003ff8758bbf4 in virNetServerProgramDispatchCall (msg=0x2aa2c3d2770, client=0x2aa2c3e3050, server=0x2aa2c3d7880, prog=0x2aa2c3d8010)
         at ../src/rpc/virnetserverprogram.c:428
  #5  virNetServerProgramDispatch (prog=0x2aa2c3d8010, server=server@entry=0x2aa2c3d7880, client=0x2aa2c3e3050, msg=0x2aa2c3d2770) at ../src/rpc/virnetserverprogram.c:302
  #6  0x000003ff8758c260 in virNetServerProcessMsg (msg=<optimized out>, prog=<optimized out>, client=<optimized out>, srv=0x2aa2c3d7880) at ../src/rpc/virnetserver.c:140
  #7  virNetServerHandleJob (jobOpaque=0x2aa2c3e2d30, opaque=0x2aa2c3d7880) at ../src/rpc/virnetserver.c:160
  #8  0x000003ff874c49aa in virThreadPoolWorker (opaque=<optimized out>) at ../src/util/virthreadpool.c:164
  #9  0x000003ff874c3f62 in virThreadHelper (data=<optimized out>) at ../src/util/virthread.c:256
  #10 0x000003ff86c1cf8c in start_thread () from /lib64/libc.so.6
  #11 0x000003ff86c9650e in thread_start () from /lib64/libc.so.6

libvirt-tck encountered the same segfault in my test environment.

Signed-off-by: Boris Fiuczynski <fiuczy@xxxxxxxxxxxxx>
---
  src/qemu/qemu_driver.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Jim Fehlig <jfehlig@xxxxxxxx>

Regards,
Jim

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index b74b0375a7..18f1156862 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -6615,7 +6615,7 @@ qemuDomainUndefineFlags(virDomainPtr dom,
          }
      }
  
-    if (vm->def->os.loader->nvram) {
+    if (vm->def->os.loader && vm->def->os.loader->nvram) {
          nvram_path = g_strdup(vm->def->os.loader->nvram);
      } else if (vm->def->os.firmware == VIR_DOMAIN_OS_DEF_FIRMWARE_EFI) {
          qemuDomainNVRAMPathFormat(cfg, vm->def, &nvram_path);







