CVE-2025-21878

What it is

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..

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-03-27 15:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 08:44 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-03-27 15:15 UTC

Last modified

2026-06-17 08:44 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-667

Record status

Modified

Affected

• Linux Kernel < 5.10.235
• Linux Kernel < 5.15.179
• Linux Kernel < 6.1.130
• Linux Kernel < 6.6.81
• Linux Kernel < 6.12.18
• Linux Kernel < 6.13.6
• Linux Kernel 6.14

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2025-21878.md and follow it. Check whether this project is affected by CVE-2025-21878. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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