| 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-2024-50222: iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP |
| |
| generic/077 on x86_32 CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP=y with highmem, |
| on huge=always tmpfs, issues a warning and then hangs (interruptibly): |
| |
| WARNING: CPU: 5 PID: 3517 at mm/highmem.c:622 kunmap_local_indexed+0x62/0xc9 |
| CPU: 5 UID: 0 PID: 3517 Comm: cp Not tainted 6.12.0-rc4 #2 |
| ... |
| copy_page_from_iter_atomic+0xa6/0x5ec |
| generic_perform_write+0xf6/0x1b4 |
| shmem_file_write_iter+0x54/0x67 |
| |
| Fix copy_page_from_iter_atomic() by limiting it in that case |
| (include/linux/skbuff.h skb_frag_must_loop() does similar). |
| |
| But going forward, perhaps CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is too |
| surprising, has outlived its usefulness, and should just be removed? |
| |
| The Linux kernel CVE team has assigned CVE-2024-50222 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.6 with commit 908a1ad89466c1febf20bfe0037b84fc66f8a3f8 and fixed in 6.6.60 with commit 4f7ffa83fa79dd52efbaef366c850aaaae06a469 |
| Issue introduced in 6.6 with commit 908a1ad89466c1febf20bfe0037b84fc66f8a3f8 and fixed in 6.11.7 with commit 3a303409f271dfe0987b8f79595138340497a32d |
| Issue introduced in 6.6 with commit 908a1ad89466c1febf20bfe0037b84fc66f8a3f8 and fixed in 6.12 with commit c749d9b7ebbc5716af7a95f7768634b30d9446ec |
| |
| 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-2024-50222 |
| 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: |
| lib/iov_iter.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/4f7ffa83fa79dd52efbaef366c850aaaae06a469 |
| https://git.kernel.org/stable/c/3a303409f271dfe0987b8f79595138340497a32d |
| https://git.kernel.org/stable/c/c749d9b7ebbc5716af7a95f7768634b30d9446ec |
