| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49828: hugetlbfs: don't delete error page from pagecache |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| hugetlbfs: don't delete error page from pagecache |
| |
| This change is very similar to the change that was made for shmem [1], and |
| it solves the same problem but for HugeTLBFS instead. |
| |
| Currently, when poison is found in a HugeTLB page, the page is removed |
| from the page cache. That means that attempting to map or read that |
| hugepage in the future will result in a new hugepage being allocated |
| instead of notifying the user that the page was poisoned. As [1] states, |
| this is effectively memory corruption. |
| |
| The fix is to leave the page in the page cache. If the user attempts to |
| use a poisoned HugeTLB page with a syscall, the syscall will fail with |
| EIO, the same error code that shmem uses. For attempts to map the page, |
| the thread will get a BUS_MCEERR_AR SIGBUS. |
| |
| [1]: commit a76054266661 ("mm: shmem: don't truncate page if memory failure happens") |
| |
| The Linux kernel CVE team has assigned CVE-2022-49828 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.80 with commit 30571f28bb35c826219971c63bcf60d2517112ed |
| Fixed in 6.0.10 with commit ec667443b2dbc6cdbbac4073e51a17733158ec6a |
| Fixed in 6.1 with commit 8625147cafaa9ba74713d682f5185eb62cb2aedb |
| |
| 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-2022-49828 |
| 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: |
| fs/hugetlbfs/inode.c |
| mm/hugetlb.c |
| mm/memory-failure.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/30571f28bb35c826219971c63bcf60d2517112ed |
| https://git.kernel.org/stable/c/ec667443b2dbc6cdbbac4073e51a17733158ec6a |
| https://git.kernel.org/stable/c/8625147cafaa9ba74713d682f5185eb62cb2aedb |
