| 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-2024-35987: riscv: Fix loading 64-bit NOMMU kernels past the start of RAM |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| riscv: Fix loading 64-bit NOMMU kernels past the start of RAM |
| |
| commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear |
| mapping") added logic to allow using RAM below the kernel load address. |
| However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the |
| kernel load address. Since that range of memory corresponds to PFNs |
| below ARCH_PFN_OFFSET, mm initialization runs off the beginning of |
| mem_map and corrupts adjacent kernel memory. Fix this by restoring the |
| previous behavior for NOMMU kernels. |
| |
| The Linux kernel CVE team has assigned CVE-2024-35987 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit 3335068f87217ea59d08f462187dc856652eea15 and fixed in 6.6.30 with commit b008e327fa570aca210f98c817757649bae56694 |
| Issue introduced in 6.4 with commit 3335068f87217ea59d08f462187dc856652eea15 and fixed in 6.8.9 with commit ea6628e4e2353978af7e3b4ad4fdaab6149acf3d |
| Issue introduced in 6.4 with commit 3335068f87217ea59d08f462187dc856652eea15 and fixed in 6.9 with commit aea702dde7e9876fb00571a2602f25130847bf0f |
| |
| 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-2024-35987 |
| 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/include/asm/page.h |
| arch/riscv/mm/init.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/b008e327fa570aca210f98c817757649bae56694 |
| https://git.kernel.org/stable/c/ea6628e4e2353978af7e3b4ad4fdaab6149acf3d |
| https://git.kernel.org/stable/c/aea702dde7e9876fb00571a2602f25130847bf0f |
