[PATCH 0/2] kvm: use anon_inode_getfd() with O_CLOEXEC flag

From: Yann Droneaud
Date: Sat Aug 24 2013 - 16:21:48 EST


Hi,

Following a patchset asking to change calls to get_unused_flag() [1]
to use O_CLOEXEC, Alex Williamson [2][3] decided to change VFIO
to use the flag.

Since it's a related subsystem to KVM, using O_CLOEXEC for
file descriptors created by KVM might be applicable too.

I'm suggesting to change calls to anon_inode_getfd() to use O_CLOEXEC
as default flag.

This patchset should be reviewed to not break existing userspace program.

BTW, if it's not applicable, I would suggest that new ioctls be added to
KVM subsystem, those ioctls would have a "flag" field added to their arguments.
Such "flag" would let userspace choose the open flag to use.
See for example other APIs using anon_inode_getfd() such as fanotify,
inotify, signalfd and timerfd.

You might be interested to read:

- Secure File Descriptor Handling (Ulrich Drepper, 2008)
http://udrepper.livejournal.com/20407.html

- Excuse me son, but your code is leaking !!! (Dan Walsh, March 2012)
http://danwalsh.livejournal.com/53603.html

Regards.

[1] http://lkml.kernel.org/r/cover.1376327678.git.ydroneaud@xxxxxxxxxx
[2] http://lkml.kernel.org/r/1377186804.25163.17.camel@xxxxxxxxxxx
[3] http://lkml.kernel.org/r/20130822171744.1297.13711.stgit@xxxxxxxxxx

Yann Droneaud (2):
kvm: use anon_inode_getfd() with O_CLOEXEC flag
ppc: kvm: use anon_inode_getfd() with O_CLOEXEC flag

arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +-
arch/powerpc/kvm/book3s_64_vio.c | 2 +-
arch/powerpc/kvm/book3s_hv.c | 2 +-
virt/kvm/kvm_main.c | 6 +++---
4 files changed, 6 insertions(+), 6 deletions(-)

--
1.8.3.1

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