| 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-2024-27070: f2fs: fix to avoid use-after-free issue in f2fs_filemap_fault |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| f2fs: fix to avoid use-after-free issue in f2fs_filemap_fault |
| |
| syzbot reports a f2fs bug as below: |
| |
| BUG: KASAN: slab-use-after-free in f2fs_filemap_fault+0xd1/0x2c0 fs/f2fs/file.c:49 |
| Read of size 8 at addr ffff88807bb22680 by task syz-executor184/5058 |
| |
| CPU: 0 PID: 5058 Comm: syz-executor184 Not tainted 6.7.0-syzkaller-09928-g052d534373b7 #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 |
| Call Trace: |
| <TASK> |
| __dump_stack lib/dump_stack.c:88 [inline] |
| dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 |
| print_address_description mm/kasan/report.c:377 [inline] |
| print_report+0x163/0x540 mm/kasan/report.c:488 |
| kasan_report+0x142/0x170 mm/kasan/report.c:601 |
| f2fs_filemap_fault+0xd1/0x2c0 fs/f2fs/file.c:49 |
| __do_fault+0x131/0x450 mm/memory.c:4376 |
| do_shared_fault mm/memory.c:4798 [inline] |
| do_fault mm/memory.c:4872 [inline] |
| do_pte_missing mm/memory.c:3745 [inline] |
| handle_pte_fault mm/memory.c:5144 [inline] |
| __handle_mm_fault+0x23b7/0x72b0 mm/memory.c:5285 |
| handle_mm_fault+0x27e/0x770 mm/memory.c:5450 |
| do_user_addr_fault arch/x86/mm/fault.c:1364 [inline] |
| handle_page_fault arch/x86/mm/fault.c:1507 [inline] |
| exc_page_fault+0x456/0x870 arch/x86/mm/fault.c:1563 |
| asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 |
| |
| The root cause is: in f2fs_filemap_fault(), vmf->vma may be not alive after |
| filemap_fault(), so it may cause use-after-free issue when accessing |
| vmf->vma->vm_flags in trace_f2fs_filemap_fault(). So it needs to keep vm_flags |
| in separated temporary variable for tracepoint use. |
| |
| The Linux kernel CVE team has assigned CVE-2024-27070 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.8 with commit 87f3afd366f7c668be0269efda8a89741a3ea6b3 and fixed in 6.8.2 with commit 8186e16a766d709a08f188d2f4e84098f364bea1 |
| Issue introduced in 6.8 with commit 87f3afd366f7c668be0269efda8a89741a3ea6b3 and fixed in 6.9 with commit eb70d5a6c932d9d23f4bb3e7b83782c21ac4b064 |
| |
| 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-2024-27070 |
| 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/f2fs/file.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/8186e16a766d709a08f188d2f4e84098f364bea1 |
| https://git.kernel.org/stable/c/eb70d5a6c932d9d23f4bb3e7b83782c21ac4b064 |
