Re: [PATCH 1/2] kvm: use anon_inode_getfd() with O_CLOEXEC flag

[Paolo Bonzini]

Il 24/08/2013 22:14, Yann Droneaud ha scritto:
 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 ydrone...@opteya.com
 Link: http://lkml.kernel.org/r/cover.1377372576.git.ydrone...@opteya.com

Reviewed-by: Paolo Bonzini pbonz...@redhat.com

 ---
  virt/kvm/kvm_main.c | 6 +++---
  1 file changed, 3 insertions(+), 3 deletions(-)
 
 diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
 index 89f74d1..d65cc0c 100644
 --- a/virt/kvm/kvm_main.c
 +++ b/virt/kvm/kvm_main.c
 @@ -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);
  }
  
  /*
 @@ -2306,7 +2306,7 @@ 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;
 @@ -2590,7 +2590,7 @@ 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);
  
 

--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH 1/2] kvm: use anon_inode_getfd() with O_CLOEXEC flag

[Yann Droneaud]

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 ydrone...@opteya.com
Link: http://lkml.kernel.org/r/cover.1377372576.git.ydrone...@opteya.com
---
 virt/kvm/kvm_main.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 89f74d1..d65cc0c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -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);
 }
 
 /*
@@ -2306,7 +2306,7 @@ 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;
@@ -2590,7 +2590,7 @@ 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);
 
-- 
1.8.3.1

--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html