CVE-2025-39731

CVE-2025-39731 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

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.

Frequently asked questions

What is CVE-2025-39731?
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.
How severe is CVE-2025-39731?
CVE-2025-39731 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-39731 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-39731?
CVE-2025-39731 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-39731?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-39731 have an EU (EUVD) identifier?
Yes. CVE-2025-39731 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-31499.
When was CVE-2025-39731 published?
CVE-2025-39731 was published on 2025-09-07 and last updated on 2026-06-17.

References

Affected products (2)

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