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CVE REMEDIATION GUIDE
Review reviewHighResearch in progress

CVE-2025-40323 remediation guide

Linux

In the Linux kernel, the following vulnerability has been resolved: fbcon: Set fb_display[i]->mode to NULL when the mode is released Recently, we discovered the following issue through syzkaller: BUG: KASAN: slab-use-after-free in fb_mode_is_equal+0x285/0x2f0 Read of size 4 at addr ff11000001b3c69c by task syz.xxx ... Call Trace: <TASK> dump_stack_lvl+0xab/0xe0 print_address_description.constprop.0+0x2c/0x390 print_report+0xb9/0x280 kasan_report+0xb8/0xf0 fb_mode_is_equal+0x285/0x2f0 fbcon_mode_deleted+0x129/0x180 fb_set_var+0xe7f/0x11d0 do_fb_ioctl+0x6a0/0x750 fb_ioctl+0xe0/0x140 __x64_sys...

Open CVE record
Research in progress

A verified fixed-version field is not available. Use the linked NVD and supporting references, then confirm the vendor-supported path before changing production systems.

ProductLinux
Affected versions>= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 39c2c1a2773aaf73e56906e5ef670114eb2d354f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 4ac18f0e6a6d599ca751c4cd98e522afc8e3d4eb, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 468f78276a37f4c6499385a4ce28f4f57be6655d, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c079d42f70109512eee49123a843be91d8fa133f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < de89d19f4f30d9a8de87b9d08c1bd35cb70576d8, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a1f3058930745d2b938b6b4f5bd9630dc74b26b7, >= 2.6.12
Fixed versionsNo verified fixed-version field is available yet
Priority basisReview · CVSS 7.8 · EPSS 0.14%
01

Identify the affected asset

Confirm whether Linux is installed, record the deployed version and installation path, and identify exposed interfaces.

  • Record the product name, package or appliance identifier, and installed version.
  • Identify internet-facing, administrative, API, and internal access paths.
  • Preserve the pre-change configuration and relevant service logs.
02

Validate the affected-version match

Compare the deployed version with the affected range: >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 39c2c1a2773aaf73e56906e5ef670114eb2d354f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 4ac18f0e6a6d599ca751c4cd98e522afc8e3d4eb, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 468f78276a37f4c6499385a4ce28f4f57be6655d, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c079d42f70109512eee49123a843be91d8fa133f, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < de89d19f4f30d9a8de87b9d08c1bd35cb70576d8, >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a1f3058930745d2b938b6b4f5bd9630dc74b26b7, >= 2.6.12. Treat incomplete inventory results as unresolved.

03

Prioritize with independent signals

The CVSS severity warrants an early asset and exposure review. Combine this signal with asset criticality, exposure, compensating controls, and business impact.

04

Apply supported remediation

Follow the vendor advisory or supported update path. Current fixed-version status: No verified fixed-version field is available yet. Preserve configuration and rollback material before change.

05

Verify the result

Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.

  • Confirm the expected version and package state.
  • Run a functional health check for critical service paths.
  • Review authentication, error, application, and security monitoring logs.
  • Reassess exposure if the supported fix cannot be applied.

Operational boundary

This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.