[PATCH 2/3] migration/cpr: Fix coverity report in cpr_exec_persist_state()

[Peter Xu <peterx@redhat.com>]

Per reported and analyzed by Peter:

https://lore.kernel.org/r/CAFEAcA_mUQ2NeoguR5efrhw7XYGofnriWEA=+Dg+Ocvyam1wAw@mail.gmail.com

mfd leak is a false positive, try to use a coverity annotation (which I
didn't find manual myself, but still give it a shot).

Fix the other one by dumping an error message if setenv() failed.

Resolves: Coverity CID 1641391
Resolves: Coverity CID 1641392
Fixes: efc6587313 ("migration: cpr-exec save and load")
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 migration/cpr-exec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/migration/cpr-exec.c b/migration/cpr-exec.c
index d57714bc5d..3cf44634a9 100644
--- a/migration/cpr-exec.c
+++ b/migration/cpr-exec.c
@@ -43,13 +43,16 @@ static QEMUFile *qemu_file_new_fd_output(int fd, const char *name)
 void cpr_exec_persist_state(QEMUFile *f)
 {
     QIOChannelFile *fioc = QIO_CHANNEL_FILE(qemu_file_get_ioc(f));
+    /* coverity[leaked_storage] - mfd intentionally kept open across exec() */
     int mfd = dup(fioc->fd);
     char val[16];
 
     /* Remember mfd in environment for post-exec load */
     qemu_clear_cloexec(mfd);
     snprintf(val, sizeof(val), "%d", mfd);
-    g_setenv(CPR_EXEC_STATE_NAME, val, 1);
+    if (!g_setenv(CPR_EXEC_STATE_NAME, val, 1)) {
+        error_report("Setting env %s = %s failed", CPR_EXEC_STATE_NAME, val);
+    }
 }
 
 static int cpr_exec_find_state(void)
-- 
2.50.1