CVE-2025-71107: f2fs: ensure node page reads complete before f2fs_put_super() finishes

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-14 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: ensure node page reads complete before f2fs_put_super() finishes Xfstests generic/335, generic/336 sometimes crash with the following message: F2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1 ------------[ cut here ]------------ kernel BUG at fs/f2fs/super.c:1939! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 1 UID: 0 PID: 609351 Comm: umount Tainted: G W 6.17.0-rc5-xfstests-g9dd1835ecda5 #1 PREEMPT(none) Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:f2fs_put_super+0x3b3/0x3c0 Call Trace: <TASK> generic_shutdown_super+0x7e/0x190 kill_block_super+0x1a/0x40 kill_f2fs_super+0x9d/0x190 deactivate_locked_super+0x30/0xb0 cleanup_mnt+0xba/0x150 task_work_run+0x5c/0xa0 exit_to_user_mode_loop+0xb7/0xc0 do_syscall_64+0x1ae/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> ---[ end trace 0000000000000000 ]--- It appears that sometimes it is possible that f2fs_put_super() is called before all node page reads are completed. Adding a call to f2fs_wait_on_all_pages() for F2FS_RD_NODE fixes the problem.

Affected products

Linux kernel: from 6.4.16 before 6.5; from 6.5.1 before 6.6.120; from 6.7 before 6.12.64; from 6.13 before 6.18.3; 6.5, 6.19-rc1, 6.19-rc2, 6.19-rc3, 6.19-rc4, 6.19-rc5 (+3) — fixed in 6.12.64, 6.18.3, 6.5, 6.6.120

How to fix

Upgrade to a fixed version: Linux kernel 6.12.64, 6.18.3, 6.5, 6.6.120. Check the vendor advisory for mitigations.

References

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