From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ahmed Abd El Mawgood Subject: [RESEND PATCH V8 10/11] KVM: Log ROE violations in system log Date: Mon, 21 Jan 2019 01:39:39 +0200 Message-Id: <20190120233940.15282-11-ahmedsoliman@mena.vt.edu> In-Reply-To: <20190120233940.15282-1-ahmedsoliman@mena.vt.edu> References: <20190120233940.15282-1-ahmedsoliman@mena.vt.edu> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: Paolo Bonzini , rkrcmar@redhat.com, Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , hpa@zytor.com, x86@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, ahmedsoliman0x666@gmail.com, ovich00@gmail.com, kernel-hardening@lists.openwall.com, nigel.edwards@hpe.com, Boris Lukashev , Igor Stoppa Cc: Ahmed Abd El Mawgood List-ID: Signed-off-by: Ahmed Abd El Mawgood --- virt/kvm/kvm_main.c | 3 ++- virt/kvm/roe.c | 25 +++++++++++++++++++++++++ virt/kvm/roe_generic.h | 3 ++- 3 files changed, 29 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d92d300539..b3dc7255b0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1945,13 +1945,14 @@ static u64 roe_gfn_to_hva(struct kvm_memory_slot *slot, gfn_t gfn, int offset, addr = __gfn_to_hva_many(slot, gfn, NULL, false); return addr; } + static int __kvm_write_guest_page(struct kvm_memory_slot *memslot, gfn_t gfn, const void *data, int offset, int len) { int r; unsigned long addr; - addr = roe_gfn_to_hva(memslot, gfn, offset, len); + kvm_roe_check_and_log(memslot, gfn, data, offset, len); if (kvm_is_error_hva(addr)) return -EFAULT; r = __copy_to_user((void __user *)addr + offset, data, len); diff --git a/virt/kvm/roe.c b/virt/kvm/roe.c index 9540473f89..e424b45e1c 100644 --- a/virt/kvm/roe.c +++ b/virt/kvm/roe.c @@ -76,6 +76,31 @@ void kvm_roe_free(struct kvm_memory_slot *slot) kvfree(slot->prot_list); } +static void kvm_warning_roe_violation(u64 addr, const void *data, int len) +{ + int i; + const char *d = data; + char *buf = kvmalloc(len * 3 + 1, GFP_KERNEL); + + for (i = 0; i < len; i++) + sprintf(buf+3*i, " %02x", d[i]); + pr_warn("ROE violation:\n"); + pr_warn("\tAttempt to write %d bytes at address 0x%08llx\n", len, addr); + pr_warn("\tData: %s\n", buf); + kvfree(buf); +} + +void kvm_roe_check_and_log(struct kvm_memory_slot *memslot, gfn_t gfn, + const void *data, int offset, int len) +{ + if (!memslot) + return; + if (!gfn_is_full_roe(memslot, gfn) && + !kvm_roe_check_range(memslot, gfn, offset, len)) + return; + kvm_warning_roe_violation((gfn << PAGE_SHIFT) + offset, data, len); +} + static void kvm_roe_protect_slot(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn, u64 npages, bool partial) { diff --git a/virt/kvm/roe_generic.h b/virt/kvm/roe_generic.h index f1ce4a8aec..6c5f0cf381 100644 --- a/virt/kvm/roe_generic.h +++ b/virt/kvm/roe_generic.h @@ -14,5 +14,6 @@ void kvm_roe_free(struct kvm_memory_slot *slot); int kvm_roe_init(struct kvm_memory_slot *slot); bool kvm_roe_check_range(struct kvm_memory_slot *slot, gfn_t gfn, int offset, int len); - +void kvm_roe_check_and_log(struct kvm_memory_slot *memslot, gfn_t gfn, + const void *data, int offset, int len); #endif -- 2.19.2