| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-36909: Drivers: hv: vmbus: Don't free ring buffers that couldn't be re-encrypted |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| Drivers: hv: vmbus: Don't free ring buffers that couldn't be re-encrypted |
| |
| In CoCo VMs it is possible for the untrusted host to cause |
| set_memory_encrypted() or set_memory_decrypted() to fail such that an |
| error is returned and the resulting memory is shared. Callers need to |
| take care to handle these errors to avoid returning decrypted (shared) |
| memory to the page allocator, which could lead to functional or security |
| issues. |
| |
| The VMBus ring buffer code could free decrypted/shared pages if |
| set_memory_decrypted() fails. Check the decrypted field in the struct |
| vmbus_gpadl for the ring buffers to decide whether to free the memory. |
| |
| The Linux kernel CVE team has assigned CVE-2024-36909 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 6.1.91 with commit 2f622008bf784a9f5dd17baa19223cc2ac30a039 |
| Fixed in 6.6.31 with commit 82f9e213b124a7d2bb5b16ea35d570260ef467e0 |
| Fixed in 6.8.10 with commit a9212a4e2963a7fbe3864ba33dc551d4ad8d0abb |
| Fixed in 6.9 with commit 30d18df6567be09c1433e81993e35e3da573ac48 |
| |
| Please see https://www.kernel.org for 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-2024-36909 |
| 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: |
| drivers/hv/channel.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/2f622008bf784a9f5dd17baa19223cc2ac30a039 |
| https://git.kernel.org/stable/c/82f9e213b124a7d2bb5b16ea35d570260ef467e0 |
| https://git.kernel.org/stable/c/a9212a4e2963a7fbe3864ba33dc551d4ad8d0abb |
| https://git.kernel.org/stable/c/30d18df6567be09c1433e81993e35e3da573ac48 |
