[PATCH v1] util/oslib-posix: Fix missing unlock in the error path of os_mem_prealloc()

[David Hildenbrand]

We're missing an unlock in case installing the signal handler failed.
Fortunately, we barely see this error in real life.

Fixes: a960d6642d39 ("util/oslib-posix: Support concurrent os_mem_prealloc() 
invocation")
Fixes: CID 1468941
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Cc: Pankaj Gupta <pankaj.gu...@ionos.com>
Cc: Daniel P. Berrangé <berra...@redhat.com>
Cc: Michal Privoznik <mpriv...@redhat.com>
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
 util/oslib-posix.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 9efdc74bba..ac0dbc2adc 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -683,6 +683,7 @@ void os_mem_prealloc(int fd, char *area, size_t memory, int 
smp_cpus,
 
         ret = sigaction(SIGBUS, &act, &sigbus_oldact);
         if (ret) {
+            qemu_mutex_unlock(&sigbus_mutex);
             error_setg_errno(errp, errno,
                 "os_mem_prealloc: failed to install signal handler");
             return;
-- 
2.33.1