IIO uses anon_inode_get() to allocate file descriptors as part 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(). KVM usage of anon_inode_getfd() was fixed in a previous patchset [1], so IIO is the only subsystem using anon_inode_getfd() with a fixed set of flags not including O_CLOEXEC. This patch set O_CLOEXEC flag on the event file descriptor created with anon_inode_getfd() to not leak file descriptors across exec(). Links: - 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 - [1] kvm: use anon_inode_getfd() with O_CLOEXEC flag http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@xxxxxxxxxx Signed-off-by: Yann Droneaud <ydroneaud@xxxxxxxxxx> Link: http://lkml.kernel.org/r/cover.1378460926.git.ydroneaud@xxxxxxxxxx --- drivers/iio/industrialio-event.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c index 10aa9ef..2390e3d 100644 --- a/drivers/iio/industrialio-event.c +++ b/drivers/iio/industrialio-event.c @@ -159,7 +159,7 @@ int iio_event_getfd(struct iio_dev *indio_dev) } spin_unlock_irq(&ev_int->wait.lock); fd = anon_inode_getfd("iio:event", - &iio_event_chrdev_fileops, ev_int, O_RDONLY); + &iio_event_chrdev_fileops, ev_int, O_RDONLY | O_CLOEXEC); if (fd < 0) { spin_lock_irq(&ev_int->wait.lock); __clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags); -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
