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| author | Marc Zyngier <maz@kernel.org> | 2019-11-13 16:05:23 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-11-13 17:13:12 +0100 |
| commit | b9876e6de123adb52ac693bac08c493e989bd93e (patch) | |
| tree | ce6d3de7b302079d4b624276a18007a9118ba838 /virt | |
| parent | 6cbee2b9eccfc1c93a03aaa286ec93331f7c95e7 (diff) | |
| download | linux-b9876e6de123adb52ac693bac08c493e989bd93e.tar.bz2 | |
KVM: Forbid /dev/kvm being opened by a compat task when CONFIG_KVM_COMPAT=n
On a system without KVM_COMPAT, we prevent IOCTLs from being issued
by a compat task. Although this prevents most silly things from
happening, it can still confuse a 32bit userspace that is able
to open the kvm device (the qemu test suite seems to be pretty
mad with this behaviour).
Take a more radical approach and return a -ENODEV to the compat
task.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 524cff24a68d..6a65ed915c7a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -124,7 +124,13 @@ static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl, #else static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) { return -EINVAL; } -#define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl + +static int kvm_no_compat_open(struct inode *inode, struct file *file) +{ + return is_compat_task() ? -ENODEV : 0; +} +#define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \ + .open = kvm_no_compat_open #endif static int hardware_enable_all(void); static void hardware_disable_all(void); |