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Vulnerabilities

Vulnerability · CVE-2026-99093

CVE-2026-99093: mm: don't schedule deferred kernel page table freeing while booting

Published Oct 26, 2026 · catalog updated Oct 28, 2026 · Linux Linux Kernel

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-99093. EPSS is 0.16%. Act only if a listed version of Linux Linux Kernel is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.16%
Remediation
Advisory link
Affected products
Linux Kernel · linux kernel · package unmanaged

In the Linux kernel, the following vulnerability has been resolved: mm: don't schedule deferred kernel page table freeing while booting Booting with a boot-time function tracer and a filter, for example ftrace=function ftrace_filter=pud_free_pmd_page panics on 7.3-rc4 as soon as the tracer starts: [ 23.531178] Starting tracer 'function' [ 23.675800] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000038: 0000 [#1] SMP KASAN NOPTI [ 23.819917] KASAN: null-ptr-deref in range [0x00000000000001c0-0x00000000000001c7] [ 23.964025] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 7.3.0-rc4-fe2ec83746e5-with-fixes-v2+ #195 PREEMPT(undef) [ 24.252248] RIP: 0010:__queue_work+0xab/0xf00 [ 25.981629] Call Trace: [ 26.125727] [ 26.413912] ? pagetable_free_kernel+0x20/0x120 [ 26.990283] queue_work_on+0x97/0xf0 [ 27.134382] __cpa_collapse_large_pages+0x501/0x6f0 [ 27.566662] cpa_flush+0x394/0x620 [ 27.998953] change_page_attr_set_clr+0x321/0x4a0 [ 29.151729] set_memory_rox+0xa2/0xf0 [ 29.584018] create_trampoline+0x431/0x6f0 ... [ 44.343347] Kernel panic - not syncing: Attempted to kill the idle task! The boot-time tracer is started from early_trace_init(), which runs before workqueue_init_early(). Making its trampoline read-only splits a large page, and CPA collapses it again right away. The split table has been a kernel page table since commit 9e4a3ec3411b ("x86/mm/pat: Allocate split page tables as kernel page tables"), so the collapse frees it through pagetable_free_kernel(), which queues work on system_percpu_wq - still NULL at that point. That commit is correct in itself; it only lets CPA reach pagetable_free_kernel() before the workqueue that function relies on exists. Keep putting the table on the list, but don't schedule the work while the system is still booting. A core_initcall schedules it once to free whatever was queued by then.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Linux Kernel6.18.53 → 6.18.57; 7.2.7 → 7.2.11
  • linux kernelversion unspecified
  • package unmanagedversion unspecified

How to fix CVE-2026-99093

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-99093. EPSS is 0.16%. Act only if a listed version of Linux Linux Kernel is installed.

Which versions are affected?

Compare what you have installed with Kernel 6.18.53 → 6.18.57; 7.2.7 → 7.2.11. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.16%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 26, 2026 · Linux Kernel CVE

    Detected

    From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: mm: don't schedule deferred kernel page table freeing while booting Booting with a boot-time function tracer and a filter, for example ftrace=function ftrace_filter=pud_free_pmd_page panics on 7.3-rc4 as soon as the tracer starts: [ 23.531178] Starting tracer 'function' [ 23.675800]

  2. Oct 28, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    Kernel fixed in 6.18.57; Kernel fixed in 7.2.11

  3. Oct 28, 2026 · OpenSSF OSV / OSV Scanner

    Fix available

    Kernel fixed in 6.18.57; 7.2.7

  4. Oct 28, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    In the Linux kernel, the following vulnerability has been resolved: mm: don't schedule deferred kernel page table freeing while booting Booting with a boot-time function tracer and a filter, for example ftrace=function ftrace_filter=pud_free_pmd_page panics on 7.3-rc4 as soon as the tracer starts: [ 23.531178] Starting tracer 'function' [ 23.675800] Oops: general protection fault, probably for non

Sources

  • CVE.orgVulnerability recordCVE-2026-99093

    Official CVE identifier

    cve.org
  • Linux Kernel CVEVendor advisoryCVE-2026-99093

    From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: mm: don't schedule deferred kernel page table freeing while booting Booting with a boot-time function tracer and a filter, for example ftrace=function ftrace_filte

    git.kernel.org
  • OpenSSF OSV / OSV ScannerPackage advisoryCVE-2026-99093

    mm: don't schedule deferred kernel page table freeing while booting

    osv.dev
  • Snyk Vulnerability DatabasePackage advisorySNYK-UNMANAGED-TORVALDSLINUX-21735696

    NULL Pointer Dereference

    security.snyk.io

References

Freshness

Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • Snyk Vulnerability DatabaseOct 29, 2026
  • OpenSSF OSV / OSV ScannerOct 28, 2026
  • Linux Kernel CVEOct 28, 2026
  • CVE.orgOct 27, 2026