| From bippy-c298863b1525 Mon Sep 17 00:00:00 2001 |
| From: gregkh@kernel.org |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-46907: KVM: VMX: Don't use vcpu->run->internal.ndata as an array index |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| KVM: VMX: Don't use vcpu->run->internal.ndata as an array index |
| |
| __vmx_handle_exit() uses vcpu->run->internal.ndata as an index for |
| an array access. Since vcpu->run is (can be) mapped to a user address |
| space with a writer permission, the 'ndata' could be updated by the |
| user process at anytime (the user process can set it to outside the |
| bounds of the array). |
| So, it is not safe that __vmx_handle_exit() uses the 'ndata' that way. |
| |
| The Linux kernel CVE team has assigned CVE-2021-46907 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.9 with commit 1aa561b1a4c0 and fixed in 5.10.32 with commit 7f64753835a7 |
| Issue introduced in 5.9 with commit 1aa561b1a4c0 and fixed in 5.11.16 with commit ce541d7b5956 |
| Issue introduced in 5.9 with commit 1aa561b1a4c0 and fixed in 5.12 with commit 04c4f2ee3f68 |
| |
| Please see https://www.kernel.org or a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-46907 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| arch/x86/kvm/vmx/vmx.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/7f64753835a78c7d2cc2932a5808ef3b7fd4c050 |
| https://git.kernel.org/stable/c/ce541d7b59566a0d94c7c99bfb5d34b050e6af70 |
| https://git.kernel.org/stable/c/04c4f2ee3f68c9a4bf1653d15f1a9a435ae33f7a |
