| 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-2024-50199: mm/swapfile: skip HugeTLB pages for unuse_vma |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| mm/swapfile: skip HugeTLB pages for unuse_vma |
| |
| I got a bad pud error and lost a 1GB HugeTLB when calling swapoff. The |
| problem can be reproduced by the following steps: |
| |
| 1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory. |
| 2. Swapout the above anonymous memory. |
| 3. run swapoff and we will get a bad pud error in kernel message: |
| |
| mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7) |
| |
| We can tell that pud_clear_bad is called by pud_none_or_clear_bad in |
| unuse_pud_range() by ftrace. And therefore the HugeTLB pages will never |
| be freed because we lost it from page table. We can skip HugeTLB pages |
| for unuse_vma to fix it. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50199 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.36 with commit 0fe6e20b9c4c53b3e97096ee73a0857f60aad43f and fixed in 5.4.285 with commit ba7f982cdb37ff5a7739dec85d7325ea66fc1496 |
| Issue introduced in 2.6.36 with commit 0fe6e20b9c4c53b3e97096ee73a0857f60aad43f and fixed in 5.10.228 with commit 417d5838ca73c6331ae2fe692fab6c25c00d9a0b |
| Issue introduced in 2.6.36 with commit 0fe6e20b9c4c53b3e97096ee73a0857f60aad43f and fixed in 5.15.169 with commit e41710f5a61aca9d6baaa8f53908a927dd9e7aa7 |
| Issue introduced in 2.6.36 with commit 0fe6e20b9c4c53b3e97096ee73a0857f60aad43f and fixed in 6.1.114 with commit 6ec0fe3756f941f42f8c57156b8bdf2877b2ebaf |
| Issue introduced in 2.6.36 with commit 0fe6e20b9c4c53b3e97096ee73a0857f60aad43f and fixed in 6.6.58 with commit bed2b9037806c62166a0ef9a559a1e7e3e1275b8 |
| Issue introduced in 2.6.36 with commit 0fe6e20b9c4c53b3e97096ee73a0857f60aad43f and fixed in 6.11.5 with commit eb66a833cdd2f7302ee05d05e0fa12a2ca32eb87 |
| Issue introduced in 2.6.36 with commit 0fe6e20b9c4c53b3e97096ee73a0857f60aad43f and fixed in 6.12 with commit 7528c4fb1237512ee18049f852f014eba80bbe8d |
| |
| 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-2024-50199 |
| 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: |
| mm/swapfile.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/ba7f982cdb37ff5a7739dec85d7325ea66fc1496 |
| https://git.kernel.org/stable/c/417d5838ca73c6331ae2fe692fab6c25c00d9a0b |
| https://git.kernel.org/stable/c/e41710f5a61aca9d6baaa8f53908a927dd9e7aa7 |
| https://git.kernel.org/stable/c/6ec0fe3756f941f42f8c57156b8bdf2877b2ebaf |
| https://git.kernel.org/stable/c/bed2b9037806c62166a0ef9a559a1e7e3e1275b8 |
| https://git.kernel.org/stable/c/eb66a833cdd2f7302ee05d05e0fa12a2ca32eb87 |
| https://git.kernel.org/stable/c/7528c4fb1237512ee18049f852f014eba80bbe8d |
