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Linux KernelOperating system · Linux

CVE-2025-21878

MEDIUM · 5.5 CVSS v3.1 Published 2025-03-27
Fix available
A fix is available. Upgrade to 5.10.235 / 5.15.179 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

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.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: i2c: npcm: disable interrupt enable bit before devm_request_irq The customer reports that there is a soft lockup issue related to the i2c driver. After checking, the i2c module was doing a tx transfer and the bmc machine reboots in the middle of the i2c transaction, the i2c module keeps the status without being reset. Due to such an i2c module status, the i2c irq handler keeps getting triggered since the i2c irq handler is registered in the kernel booting process after the bmc machine is doing a warm rebooting. The continuous triggering is stopped by the soft lockup watchdog timer. Disable the interrupt enable bit in the i2c module before calling devm_request_irq to fix this issue since the i2c relative status bit is read-only. Here is the soft lockup log. [ 28.176395] watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [swapper/0:1] [ 28.183351] Modules linked in: [ 28.186407] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.120-yocto-s-dirty-bbebc78 #1 [ 28.201174] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 28.208128] pc : __do_softirq+0xb0/0x368 [ 28.212055] lr : __do_softirq+0x70/0x368 [ 28.215972] sp : ffffff8035ebca00 [ 28.219278] x29: ffffff8035ebca00 x28: 0000000000000002 x27: ffffff80071a3780 [ 28.226412] x26: ffffffc008bdc000 x25: ffffffc008bcc640 x24: ffffffc008be50c0 [ 28.233546] x23: ffffffc00800200c x22: 0000000000000000 x21: 000000000000001b [ 28.240679] x20: 0000000000000000 x19: ffffff80001c3200 x18: ffffffffffffffff [ 28.247812] x17: ffffffc02d2e0000 x16: ffffff8035eb8b40 x15: 00001e8480000000 [ 28.254945] x14: 02c3647e37dbfcb6 x13: 02c364f2ab14200c x12: 0000000002c364f2 [ 28.262078] x11: 00000000fa83b2da x10: 000000000000b67e x9 : ffffffc008010250 [ 28.269211] x8 : 000000009d983d00 x7 : 7fffffffffffffff x6 : 0000036d74732434 [ 28.276344] x5 : 00ffffffffffffff x4 : 0000000000000015 x3 : 0000000000000198 [ 28.283476] x2 : ffffffc02d2e0000 x1 : 00000000000000e0 x0 : ffffffc008bdcb40 [ 28.290611] Call trace: [ 28.293052] __do_softirq+0xb0/0x368 [ 28.296625] __irq_exit_rcu+0xe0/0x100 [ 28.300374] irq_exit+0x14/0x20 [ 28.303513] handle_domain_irq+0x68/0x90 [ 28.307440] gic_handle_irq+0x78/0xb0 [ 28.311098] call_on_irq_stack+0x20/0x38 [ 28.315019] do_interrupt_handler+0x54/0x5c [ 28.319199] el1_interrupt+0x2c/0x4c [ 28.322777] el1h_64_irq_handler+0x14/0x20 [ 28.326872] el1h_64_irq+0x74/0x78 [ 28.330269] __setup_irq+0x454/0x780 [ 28.333841] request_threaded_irq+0xd0/0x1b4 [ 28.338107] devm_request_threaded_irq+0x84/0x100 [ 28.342809] npcm_i2c_probe_bus+0x188/0x3d0 [ 28.346990] platform_probe+0x6c/0xc4 [ 28.350653] really_probe+0xcc/0x45c [ 28.354227] __driver_probe_device+0x8c/0x160 [ 28.358578] driver_probe_device+0x44/0xe0 [ 28.362670] __driver_attach+0x124/0x1d0 [ 28.366589] bus_for_each_dev+0x7c/0xe0 [ 28.370426] driver_attach+0x28/0x30 [ 28.373997] bus_add_driver+0x124/0x240 [ 28.377830] driver_register+0x7c/0x124 [ 28.381662] __platform_driver_register+0x2c/0x34 [ 28.386362] npcm_i2c_init+0x3c/0x5c [ 28.389937] do_one_initcall+0x74/0x230 [ 28.393768] kernel_init_freeable+0x24c/0x2b4 [ 28.398126] kernel_init+0x28/0x130 [ 28.401614] ret_from_fork+0x10/0x20 [ 28.405189] Kernel panic - not syncing: softlockup: hung tasks [ 28.411011] SMP: stopping secondary CPUs [ 28.414933] Kernel Offset: disabled [ 28.418412] CPU features: 0x00000000,00000802 [ 28.427644] Rebooting in 20 seconds..

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.

dbcve analysis
How this class of weakness works · CWE-667

Shared resources are accessed without correct locking, so concurrent operations interleave into inconsistent — and sometimes exploitable — states, or deadlock the service outright. These bugs are subtle and timing-dependent. The fix is correct, consistent locking or atomic operations around every shared resource.

General guidance for the improper locking class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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.

NVD · CPE data
Linux KernelOperating system
Affected:>= 5.8, < 5.10.235>= 5.11, < 5.15.179>= 5.16, < 6.1.130>= 6.2, < 6.6.81>= 6.7, < 6.12.18>= 6.13, < 6.13.6= 6.14

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.

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 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.

dbcve · scoped
Upgrade available Upgrade to 5.10.235 / 5.15.179 / 6.1.130 or later
Fixed in 5.10.2355.15.1796.1.130
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux kernel 6.6.81 (or latest stable LTS such as 6.1.x, 5.15.x, or 5.10.x at their respective fixed versions)

  1. Upgrade the Linux kernel to a version that includes the fix: Linux 5.10.235 or later, 5.15.179 or later, 6.1.130 or later, or 6.6.81 or later
  2. The fix (commit 12d0e39916705b68d2d8ba20a8e35d1d27afc260) modifies the i2c npcm driver to disable the interrupt enable bit in the I2C module before calling devm_request_irq
  3. This prevents the IRQ handler from being triggered by stale I2C status bits during driver probe, which was causing the soft lockup

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

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

Primary sources

Practitioner notes

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