CVE-2024-39467 f2fs: fix to do sanity check on i_xattr_nid in sanity_check_inode()
A missing sanity check in the Linux kernel's F2FS filesystem allows out-of-bounds memory access, potentially causing a system crash.
- 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-2024-39467?
CVE-2024-39467 is a high-severity memory corruption vulnerability in Linux kernel, published on 25 Jun 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 do sanity check on i_xattr_nid in sanity_check_inode()
syzbot reports a kernel bug as below:
F2FS-fs (loop0): Mounted with checkpoint version = 48b305e4 ================================================================== BUG: KASAN: slab-out-of-bounds in f2fs_test_bit fs/f2fs/f2fs.h:2933 [inline] BUG: KASAN: slab-out-of-bounds in current_nat_addr fs/f2fs/node.h:213 [inline] BUG: KASAN: slab-out-of-bounds in f2fs_get_node_info+0xece/0x1200 fs/f2fs/node.c:600 Read of size 1 at addr ffff88807a58c76c by task syz-executor280/5076
CPU: 1 PID: 5076 Comm: syz-executor280 Not tainted 6.9.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 f2fs_test_bit fs/f2fs/f2fs.h:2933 [inline] current_nat_addr fs/f2fs/node.h:213 [inline] f2fs_get_node_info+0xece/0x1200 fs/f2fs/node.c:600 f2fs_xattr_fiemap fs/f2fs/data.c:1848 [inline] f2fs_fiemap+0x55d/0x1ee0 fs/f2fs/data.c:1925 ioctl_fiemap fs/ioctl.c:220 [inline] do_vfs_ioctl+0x1c07/0x2e50 fs/ioctl.c:838 __do_sys_ioctl fs/ioctl.c:902 [inline] __se_sys_ioctl+0x81/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f
The root cause is we missed to do sanity check on i_xattr_nid during f2fs_iget(), so that in fiemap() path, current_nat_addr() will access nat_bitmap w/ offset from invalid i_xattr_nid, result in triggering kasan bug report, fix it.
Weakness: CWE-125
Which versions are affected by CVE-2024-39467?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-39467?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2024-39467 being exploited?
There is no known exploitation of CVE-2024-39467 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-39467, DEBIAN-CVE-2024-39467, GHSA-wpx2-jqxx-pcch, UBUNTU-CVE-2024-39467.