CVE-2024-49887 f2fs: fix to don't panic system for no free segment fault injection

Medium 5.5 Published 21 Oct 2024 Updated 11 May 2026

A local attacker can trigger a kernel panic in the f2fs filesystem via fault injection, causing a system-wide denial of service.

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-2024-49887?

CVE-2024-49887 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 Oct 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 don't panic system for no free segment fault injection

syzbot reports a f2fs bug as below:

F2FS-fs (loop0): inject no free segment in get_new_segment of __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167 F2FS-fs (loop0): Stopped filesystem due to reason: 7 ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:2748! CPU: 0 UID: 0 PID: 5109 Comm: syz-executor304 Not tainted 6.11.0-rc6-syzkaller-00363-g89f5e14d05b4 #0 RIP: 0010:get_new_segment fs/f2fs/segment.c:2748 [inline] RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836 Call Trace: __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167 f2fs_allocate_new_section fs/f2fs/segment.c:3181 [inline] f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3195 f2fs_expand_inode_data+0x5d6/0xbb0 fs/f2fs/file.c:1799 f2fs_fallocate+0x448/0x960 fs/f2fs/file.c:1903 vfs_fallocate+0x553/0x6c0 fs/open.c:334 do_vfs_ioctl+0x2592/0x2e50 fs/ioctl.c:886 __do_sys_ioctl fs/ioctl.c:905 [inline] __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893 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:get_new_segment fs/f2fs/segment.c:2748 [inline] RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836

The root cause is when we inject no free segment fault into f2fs, we should not panic system, fix it.

Which versions are affected by CVE-2024-49887?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-49887?

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-2024-49887 being exploited?

There is no known exploitation of CVE-2024-49887 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2024-49887, DEBIAN-CVE-2024-49887, GHSA-c3cx-mm7p-wgj8, ROOT-OS-UBUNTU-2404-CVE-2024-49887, UBUNTU-CVE-2024-49887.