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medium 5.5

CVE-2025-39731 json

f2fs: vm_unmap_ram() may be called from an invalid context

published last yr. modified 21d ago also EUVD-2025-31499

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

f2fs: vm_unmap_ram() may be called from an invalid context

When testing F2FS with xfstests using UFS backed virtual disks the kernel complains sometimes that f2fs_release_decomp_mem() calls vm_unmap_ram() from an invalid context. Example trace from f2fs/007 test:

f2fs/007 5s ... [12:59:38][ 8.902525] run fstests f2fs/007 [ 11.468026] BUG: sleeping function called from invalid context at mm/vmalloc.c:2978 [ 11.471849] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 68, name: irq/22-ufshcd [ 11.475357] preempt_count: 1, expected: 0 [ 11.476970] RCU nest depth: 0, expected: 0 [ 11.478531] CPU: 0 UID: 0 PID: 68 Comm: irq/22-ufshcd Tainted: G W 6.16.0-rc5-xfstests-ufs-g40f92e79b0aa #9 PREEMPT(none) [ 11.478535] Tainted: [W]=WARN [ 11.478536] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 11.478537] Call Trace: [ 11.478543] <TASK> [ 11.478545] dump_stack_lvl+0x4e/0x70 [ 11.478554] __might_resched.cold+0xaf/0xbe [ 11.478557] vm_unmap_ram+0x21/0xb0 [ 11.478560] f2fs_release_decomp_mem+0x59/0x80 [ 11.478563] f2fs_free_dic+0x18/0x1a0 [ 11.478565] f2fs_finish_read_bio+0xd7/0x290 [ 11.478570] blk_update_request+0xec/0x3b0 [ 11.478574] ? sbitmap_queue_clear+0x3b/0x60 [ 11.478576] scsi_end_request+0x27/0x1a0 [ 11.478582] scsi_io_completion+0x40/0x300 [ 11.478583] ufshcd_mcq_poll_cqe_lock+0xa3/0xe0 [ 11.478588] ufshcd_sl_intr+0x194/0x1f0 [ 11.478592] ufshcd_threaded_intr+0x68/0xb0 [ 11.478594] ? __pfx_irq_thread_fn+0x10/0x10 [ 11.478599] irq_thread_fn+0x20/0x60 [ 11.478602] ? __pfx_irq_thread_fn+0x10/0x10 [ 11.478603] irq_thread+0xb9/0x180 [ 11.478605] ? __pfx_irq_thread_dtor+0x10/0x10 [ 11.478607] ? __pfx_irq_thread+0x10/0x10 [ 11.478609] kthread+0x10a/0x230 [ 11.478614] ? __pfx_kthread+0x10/0x10 [ 11.478615] ret_from_fork+0x7e/0xd0 [ 11.478619] ? __pfx_kthread+0x10/0x10 [ 11.478621] ret_from_fork_asm+0x1a/0x30 [ 11.478623] </TASK>

This patch modifies in_task() check inside f2fs_read_end_io() to also check if interrupts are disabled. This ensures that pages are unmapped asynchronously in an interrupt handler.

Patch / fix

  • Linux Linux 6.1.148, 6.6.102, 6.12.42, 6.15.10, 6.16.1, 6.17
  • linux Debian 12 6.1.148-1
  • linux Debian 13 6.12.43-1
  • linux Debian 14 6.16.3-1

debian advisories DEBIAN-CVE-2025-39731

  • linux Ubuntu 24.04 LTS 6.8.0-100.100
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1046.49
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1047.50
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1043.48
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1044.44
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1046.52
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1030.33
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1047.51

ubuntu advisories UBUNTU-CVE-2025-39731

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-39731 updated

kernel: f2fs: vm_unmap_ram() may be called from an invalid context

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

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References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.