CVE-2024-56692 f2fs: fix to do sanity check on node blkaddr in truncate_node()
A local attacker can cause a kernel panic and system crash by mounting a specially crafted f2fs filesystem image with corrupted node block addresses.
- 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-2024-56692?
CVE-2024-56692 is a high-severity denial of service vulnerability in Linux kernel, published on 28 Dec 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 node blkaddr in truncate_node()
syzbot reports a f2fs bug as below:
------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:2534! RIP: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534 Call Trace: truncate_node+0x1ae/0x8c0 fs/f2fs/node.c:909 f2fs_remove_inode_page+0x5c2/0x870 fs/f2fs/node.c:1288 f2fs_evict_inode+0x879/0x15c0 fs/f2fs/inode.c:856 evict+0x4e8/0x9b0 fs/inode.c:723 f2fs_handle_failed_inode+0x271/0x2e0 fs/f2fs/inode.c:986 f2fs_create+0x357/0x530 fs/f2fs/namei.c:394 lookup_open fs/namei.c:3595 [inline] open_last_lookups fs/namei.c:3694 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3930 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534
The root cause is: on a fuzzed image, blkaddr in nat entry may be corrupted, then it will cause system panic when using it in f2fs_invalidate_blocks(), to avoid this, let's add sanity check on nat blkaddr in truncate_node().
Weakness: CWE-754
Which versions are affected by CVE-2024-56692?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-56692?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-56692 being exploited?
There is no known exploitation of CVE-2024-56692 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-55739, AZL-55804, BELL-CVE-2024-56692, DEBIAN-CVE-2024-56692, GHSA-hc7h-3x34-frvv, ROOT-OS-DEBIAN-11-CVE-2024-56692 and 3 more.