diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2021-12-10 19:36:20 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-01-07 18:44:44 +0300 |
| commit | 2efd61a608b0039911924d2e5d7028eb37496e85 (patch) | |
| tree | 26f889c3710b9b263c0f2c748a6882ddc4e41971 /include/linux/kvm_dirty_ring.h | |
| parent | f3f26dae05e39f0f286f588669b54d49b61dcfb8 (diff) | |
| download | linux-2efd61a608b0039911924d2e5d7028eb37496e85.tar.xz | |
KVM: Warn if mark_page_dirty() is called without an active vCPU
The various kvm_write_guest() and mark_page_dirty() functions must only
ever be called in the context of an active vCPU, because if dirty ring
tracking is enabled it may simply oops when kvm_get_running_vcpu()
returns NULL for the vcpu and then kvm_dirty_ring_get() dereferences it.
This oops was reported by "butt3rflyh4ck" <butterflyhuangxx@gmail.com> in
https://lore.kernel.org/kvm/CAFcO6XOmoS7EacN_n6v4Txk7xL7iqRa2gABg3F7E3Naf5uG94g@mail.gmail.com/
That actual bug will be fixed under separate cover but this warning
should help to prevent new ones from being added.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Message-Id: <20211210163625.2886-2-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/linux/kvm_dirty_ring.h')
| -rw-r--r-- | include/linux/kvm_dirty_ring.h | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h index 4da8d4a4140b..906f899813dc 100644 --- a/include/linux/kvm_dirty_ring.h +++ b/include/linux/kvm_dirty_ring.h @@ -43,11 +43,6 @@ static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, return 0; } -static inline struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm) -{ - return NULL; -} - static inline int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring) { @@ -78,7 +73,6 @@ static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring) u32 kvm_dirty_ring_get_rsvd_entries(void); int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size); -struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm); /* * called with kvm->slots_lock held, returns the number of |