| 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-2024-49856: x86/sgx: Fix deadlock in SGX NUMA node search |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| x86/sgx: Fix deadlock in SGX NUMA node search |
| |
| When the current node doesn't have an EPC section configured by firmware |
| and all other EPC sections are used up, CPU can get stuck inside the |
| while loop that looks for an available EPC page from remote nodes |
| indefinitely, leading to a soft lockup. Note how nid_of_current will |
| never be equal to nid in that while loop because nid_of_current is not |
| set in sgx_numa_mask. |
| |
| Also worth mentioning is that it's perfectly fine for the firmware not |
| to setup an EPC section on a node. While setting up an EPC section on |
| each node can enhance performance, it is not a requirement for |
| functionality. |
| |
| Rework the loop to start and end on *a* node that has SGX memory. This |
| avoids the deadlock looking for the current SGX-lacking node to show up |
| in the loop when it never will. |
| |
| The Linux kernel CVE team has assigned CVE-2024-49856 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.13 with commit 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 and fixed in 5.15.168 with commit 40fb64257dab507d86b5f1f2a62f3669ef0c91a8 |
| Issue introduced in 5.13 with commit 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 and fixed in 6.1.113 with commit 20c96d0aaabfe361fc2a11c173968dc67feadbbf |
| Issue introduced in 5.13 with commit 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 and fixed in 6.6.54 with commit fb2d057539eda67ec7cfc369bf587e6518a9b99d |
| Issue introduced in 5.13 with commit 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 and fixed in 6.10.13 with commit 0f89fb4042c08fd143bfc28af08bf6c8a0197eea |
| Issue introduced in 5.13 with commit 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 and fixed in 6.11.2 with commit 8132510c915815e6b537ab937d94ed66893bc7b8 |
| Issue introduced in 5.13 with commit 901ddbb9ecf5425183ea0c09d10c2fd7868dce54 and fixed in 6.12 with commit 9c936844010466535bd46ea4ce4656ef17653644 |
| |
| 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-2024-49856 |
| 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/kernel/cpu/sgx/main.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/40fb64257dab507d86b5f1f2a62f3669ef0c91a8 |
| https://git.kernel.org/stable/c/20c96d0aaabfe361fc2a11c173968dc67feadbbf |
| https://git.kernel.org/stable/c/fb2d057539eda67ec7cfc369bf587e6518a9b99d |
| https://git.kernel.org/stable/c/0f89fb4042c08fd143bfc28af08bf6c8a0197eea |
| https://git.kernel.org/stable/c/8132510c915815e6b537ab937d94ed66893bc7b8 |
| https://git.kernel.org/stable/c/9c936844010466535bd46ea4ce4656ef17653644 |
