| 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-2024-38667: riscv: prevent pt_regs corruption for secondary idle threads |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| riscv: prevent pt_regs corruption for secondary idle threads |
| |
| Top of the kernel thread stack should be reserved for pt_regs. However |
| this is not the case for the idle threads of the secondary boot harts. |
| Their stacks overlap with their pt_regs, so both may get corrupted. |
| |
| Similar issue has been fixed for the primary hart, see c7cdd96eca28 |
| ("riscv: prevent stack corruption by reserving task_pt_regs(p) early"). |
| However that fix was not propagated to the secondary harts. The problem |
| has been noticed in some CPU hotplug tests with V enabled. The function |
| smp_callin stored several registers on stack, corrupting top of pt_regs |
| structure including status field. As a result, kernel attempted to save |
| or restore inexistent V context. |
| |
| The Linux kernel CVE team has assigned CVE-2024-38667 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.7 with commit 2875fe0561569f82d0e63658ccf0d11ce7da8922 and fixed in 6.1.93 with commit ea22d4195cca13d5fdbc4d6555a2dfb8a7867a9e |
| Issue introduced in 5.7 with commit 2875fe0561569f82d0e63658ccf0d11ce7da8922 and fixed in 6.6.33 with commit 3090c06d50eaa91317f84bf3eac4c265e6cb8d44 |
| Issue introduced in 5.7 with commit 2875fe0561569f82d0e63658ccf0d11ce7da8922 and fixed in 6.9.4 with commit 0c1f28c32a194303da630fca89481334b9547b80 |
| Issue introduced in 5.7 with commit 2875fe0561569f82d0e63658ccf0d11ce7da8922 and fixed in 6.10 with commit a638b0461b58aa3205cd9d5f14d6f703d795b4af |
| |
| 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-2024-38667 |
| 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/riscv/kernel/cpu_ops_sbi.c |
| arch/riscv/kernel/cpu_ops_spinwait.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/ea22d4195cca13d5fdbc4d6555a2dfb8a7867a9e |
| https://git.kernel.org/stable/c/3090c06d50eaa91317f84bf3eac4c265e6cb8d44 |
| https://git.kernel.org/stable/c/0c1f28c32a194303da630fca89481334b9547b80 |
| https://git.kernel.org/stable/c/a638b0461b58aa3205cd9d5f14d6f703d795b4af |
