CVE-2024-27070 f2fs: fix to avoid use-after-free issue in f2fs_filemap_fault
A use-after-free vulnerability in the Linux kernel's f2fs filesystem allows local attackers to potentially execute arbitrary code or escalate privileges.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-27070?
CVE-2024-27070 is a high-severity use after free vulnerability in Linux kernel, published on 1 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-416
Which versions are affected by CVE-2024-27070?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-27070?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2024-27070 being exploited?
There is no known exploitation of CVE-2024-27070 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-27070, GHSA-8xwv-9gjh-23gh, UBUNTU-CVE-2024-27070.