diff options
| author | Jim Mattson <jmattson@google.com> | 2018-12-14 23:34:43 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-12-21 11:28:22 +0100 |
| commit | 7a86dab8cf2f0fdf508f3555dddfc236623bff60 (patch) | |
| tree | db2444964b752655491d4a27e012f90d227f110f | |
| parent | kvm: Disallow wraparound in kvm_gfn_to_hva_cache_init (diff) | |
| download | linux-7a86dab8cf2f0fdf508f3555dddfc236623bff60.tar.xz linux-7a86dab8cf2f0fdf508f3555dddfc236623bff60.zip | |
kvm: Change offset in kvm_write_guest_offset_cached to unsigned
Since the offset is added directly to the hva from the
gfn_to_hva_cache, a negative offset could result in an out of bounds
write. The existing BUG_ON only checks for addresses beyond the end of
the gfn_to_hva_cache, not for addresses before the start of the
gfn_to_hva_cache.
Note that all current call sites have non-negative offsets.
Fixes: 4ec6e8636256 ("kvm: Introduce kvm_write_guest_offset_cached()")
Reported-by: Cfir Cohen <cfir@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Cfir Cohen <cfir@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| -rw-r--r-- | include/linux/kvm_host.h | 3 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index e065aeaae29e..c38cc5eb7e73 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -695,7 +695,8 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len); int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, - void *data, int offset, unsigned long len); + void *data, unsigned int offset, + unsigned long len); int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len); int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3be46841db06..f90ceab3840e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2043,7 +2043,8 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init); int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, - void *data, int offset, unsigned long len) + void *data, unsigned int offset, + unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r; |