On Tue, Feb 13, 2024 at 04:42:27PM +0000, Sebastian Ene wrote:

On Tue, Feb 13, 2024 at 12:56:20AM +0000, Oliver Upton wrote:

quoted

On Wed, Feb 07, 2024 at 02:48:32PM +0000, Sebastian Ene wrote:

[...]

quoted

quoted

+static int kvm_ptdump_guest_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, kvm_ptdump_guest_show, inode->i_private);
+}
+

Shouldn't we take a reference on the KVM struct at open to avoid UAF?

	struct kvm *kvm = inode->i_private;

	if (!kvm_get_kvm_safe(kvm))
		return -ENOENT;

Then you can do a put on it at close().

Thanks, I though that the kvm_destroy_vm_debugfs will keep spinning if
there are opened paths to the debugfs entry, but I guess nothing prevents
that from happening and the kvm struct can be removed behind our back.

kvm_destroy_vm() will get called after the last put() on a kvm struct,
so all debugfs files should be closed too if we're consistent about
this.

-- 
Thanks,
Oliver

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