Commit 24009b05 authored Aug 24, 2013 by Yann Droneaud Committed by Gleb Natapov Aug 26, 2013

kvm: use anon_inode_getfd() with O_CLOEXEC flag



KVM uses anon_inode_get() to allocate file descriptors as part
of some of its ioctls. But those ioctls are lacking a flag argument
allowing userspace to choose options for the newly opened file descriptor.

In such case it's advised to use O_CLOEXEC by default so that
userspace is allowed to choose, without race, if the file descriptor
is going to be inherited across exec().

This patch set O_CLOEXEC flag on all file descriptors created
with anon_inode_getfd() to not leak file descriptors across exec().

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com


Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

parent 9bc6cbeb

virt/kvm/kvm_main.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1896,7 +1896,7 @@ static struct file_operations kvm_vcpu_fops = {
		*/
		static int create_vcpu_fd(struct kvm_vcpu *vcpu)
		{
		return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
		return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR \| O_CLOEXEC);
		}

		/*
		@@ -2305,7 +2305,7 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
		return ret;
		}

		ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR);
		ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR \| O_CLOEXEC);
		if (ret < 0) {
		ops->destroy(dev);
		return ret;
		@@ -2589,7 +2589,7 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
		return r;
		}
		#endif
		r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
		r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR \| O_CLOEXEC);
		if (r < 0)
		kvm_put_kvm(kvm);

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