Linux KernelOperating system · Linux

CVE-2025-39907

MEDIUM · 5.5 CVSS v3.1 Published 2025-10-01

Fix available

A fix is available. Upgrade to 5.4.300 / 5.10.245 or later.

See remediation →

57/100

Remediation priority · Elevated

Zero-click Patch available

Official description

NVD · unedited

In the Linux kernel, the following vulnerability has been resolved: mtd: rawnand: stm32_fmc2: avoid overlapping mappings on ECC buffer Avoid below overlapping mappings by using a contiguous non-cacheable buffer. [ 4.077708] DMA-API: stm32_fmc2_nfc 48810000.nand-controller: cacheline tracking EEXIST, overlapping mappings aren't supported [ 4.089103] WARNING: CPU: 1 PID: 44 at kernel/dma/debug.c:568 add_dma_entry+0x23c/0x300 [ 4.097071] Modules linked in: [ 4.100101] CPU: 1 PID: 44 Comm: kworker/u4:2 Not tainted 6.1.82 #1 [ 4.106346] Hardware name: STMicroelectronics STM32MP257F VALID1 SNOR / MB1704 (LPDDR4 Power discrete) + MB1703 + MB1708 (SNOR MB1730) (DT) [ 4.118824] Workqueue: events_unbound deferred_probe_work_func [ 4.124674] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 4.131624] pc : add_dma_entry+0x23c/0x300 [ 4.135658] lr : add_dma_entry+0x23c/0x300 [ 4.139792] sp : ffff800009dbb490 [ 4.143016] x29: ffff800009dbb4a0 x28: 0000000004008022 x27: ffff8000098a6000 [ 4.150174] x26: 0000000000000000 x25: ffff8000099e7000 x24: ffff8000099e7de8 [ 4.157231] x23: 00000000ffffffff x22: 0000000000000000 x21: ffff8000098a6a20 [ 4.164388] x20: ffff000080964180 x19: ffff800009819ba0 x18: 0000000000000006 [ 4.171545] x17: 6361727420656e69 x16: 6c6568636163203a x15: 72656c6c6f72746e [ 4.178602] x14: 6f632d646e616e2e x13: ffff800009832f58 x12: 00000000000004ec [ 4.185759] x11: 00000000000001a4 x10: ffff80000988af58 x9 : ffff800009832f58 [ 4.192916] x8 : 00000000ffffefff x7 : ffff80000988af58 x6 : 80000000fffff000 [ 4.199972] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000 [ 4.207128] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000812d2c40 [ 4.214185] Call trace: [ 4.216605] add_dma_entry+0x23c/0x300 [ 4.220338] debug_dma_map_sg+0x198/0x350 [ 4.224373] __dma_map_sg_attrs+0xa0/0x110 [ 4.228411] dma_map_sg_attrs+0x10/0x2c [ 4.232247] stm32_fmc2_nfc_xfer.isra.0+0x1c8/0x3fc [ 4.237088] stm32_fmc2_nfc_seq_read_page+0xc8/0x174 [ 4.242127] nand_read_oob+0x1d4/0x8e0 [ 4.245861] mtd_read_oob_std+0x58/0x84 [ 4.249596] mtd_read_oob+0x90/0x150 [ 4.253231] mtd_read+0x68/0xac

Technical summary

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions

NVD · CPE data

Linux KernelOperating system

Affected:>= 5.1, < 5.4.300>= 5.5, < 5.10.245>= 5.11, < 5.15.194>= 5.16, < 6.1.153>= 6.2, < 6.6.107>= 6.7, < 6.12.48>= 6.13, < 6.16.8= 6.17

Debian LinuxOperating system

Affected:= 11.0

CVSS breakdown

From the vector

Attack vector: Local
Complexity: Low
Privileges: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation

dbcve · scoped

Upgrade available Upgrade to 5.4.300 / 5.10.245 / 5.15.194 or later

Fixed in 5.4.3005.10.2455.15.194

Vendor patch git.kernel.org →

Recommended fix High confidence

Linux kernel >= 5.4.300, >= 5.10.245, >= 5.15.194, or >= 6.1.153 (Debian 11: upgrade to a kernel version that includes the fix, typically 5.10.x from Debian 11.12+ or later)

Identify the current kernel version using `uname -r`
For Debian 11.0, upgrade the kernel package via: `apt update && apt upgrade linux-image-arm64` (or `linux-image-armhf` for 32-bit)
Reboot the system to load the new kernel
Verify the fix is applied by checking the kernel version is >= 5.10.245 (for Debian 11)

Caveat Standard kernel upgrade风险 - ensure bootloader is configured correctly and verify hardware compatibility before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

Scan for this in your stack

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References

Primary sources

git.kernel.orgPatch / commit
git.kernel.orgPatch
git.kernel.orgPatch
git.kernel.orgPatch
git.kernel.orgPatch
git.kernel.orgPatch
git.kernel.orgPatch
git.kernel.orgPatch
git.kernel.orgPatch
lists.debian.orgMailing ListThird Party Advisory
nvd.nist.govNVD record

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-39907 in production — separate from our analysis above.

Notes0 Guidelines

Know something about CVE-2025-39907?

The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.

The version that genuinely resolved it — not the one the vendor claimed
A config change or rule that shut the vector down
A gotcha in the upgrade path that cost you an afternoon

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here

Verified mitigations, workarounds, and config changes
Version or environment caveats, and links to real fixes
No weaponised exploit code, or anything meant to cause harm
No spam, self-promotion, credentials, or personal data

At a glance

A fix existsUpgrade to 5.4.300 / 5.10.245 or later

Severity 5.5 Medium

Exploit likelihood EPSS, next 30 days 0.1%

Affects: Linux Kernel

Remediation

Need this fixed?

Get a fix

Estimated effortfrom ~9 hrs

ComplexityModerate

Typical engagementfrom $1,600

What a fix involves

We scope it with you and confirm a fixed quote
A specialist builds a reviewed fix
You deploy it to staging first
Optional re-test once it’s live

We specialise in CVE remediation. Send your environment and we’ll scope CVE-2025-39907 and return a fixed quote.

You’ll deal with our team directly and deploy the reviewed fix to staging first — never straight to production.

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

Scan for this in your stack

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Practitioner notes

No notes yet

Official description

Technical summary

Affected products & versions

CVSS breakdown

Remediation

References