KVM: explain missing kvm_put_kvm in case of failure

The call to kvm_put_kvm was removed from error handling in commit 506cfba ("KVM: don't use anon_inode_getfd() before possible failures"), but it is _not_ a memory leak. Reuse Al's explanation to avoid that someone else makes the same mistake. Signed-off-by: Paolo Bonzini <[email protected]>
josf · Jun 27, 2017 · 525df86 · 525df86
1 parent 039c5d1
commit 525df86
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
@@ -3191,6 +3191,12 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
 		return PTR_ERR(file);
 	}
 
+	/*
+	 * Don't call kvm_put_kvm anymore at this point; file->f_op is
+	 * already set, with ->release() being kvm_vm_release().  In error
+	 * cases it will be called by the final fput(file) and will take
+	 * care of doing kvm_put_kvm(kvm).
+	 */
 	if (kvm_create_vm_debugfs(kvm, r) < 0) {
 		put_unused_fd(r);
 		fput(file);