LiveActive security incident?Get immediate response
CVE Record

CVE-2022-48870: tty: fix possible null-ptr-defer in spk_ttyio_release

In the Linux kernel, the following vulnerability has been resolved: tty: fix possible null-ptr-defer in spk_ttyio_release Run the following tests on the qemu platform: syzkaller:~# modprobe speakup_audptr input: Speakup as /devices/virtual/input/input4 initialized device: /dev/synth, node (MAJOR 10, MINOR 125) speakup 3.1.6: initialized synth name on entry is: (null) synth probe spk_ttyio_initialise_ldisc failed because tty_kopen_exclusive returned failed (errno -16), then remove the module, we will get a null-ptr-defer problem, as follow: syzkaller:~# modprobe -r speakup_audptr releasing synth audptr BUG: kernel NULL pointer dereference, address: 0000000000000080 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 2 PID: 204 Comm: modprobe Not tainted 6.1.0-rc6-dirty #1 RIP: 0010:mutex_lock+0x14/0x30 Call Trace: <TASK> spk_ttyio_release+0x19/0x70 [speakup] synth_release.part.6+0xac/0xc0 [speakup] synth_remove+0x56/0x60 [speakup] __x64_sys_delete_module+0x156/0x250 ? fpregs_assert_state_consistent+0x1d/0x50 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> Modules linked in: speakup_audptr(-) speakup Dumping ftrace buffer: in_synth->dev was not initialized during modprobe, so we add check for in_synth->dev to fix this bug.

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

CVE-2022-48870 is a Linux kernel bug in the Speakup accessibility driver path. A failed TTY initialization can leave a device pointer unset, and later cleanup can dereference it, causing a kernel crash. The sources do not show data theft, privilege escalation, or active exploitation.

Executive priority

Treat this as routine kernel maintenance unless your environment exposes Speakup modules on shared or high-availability Linux systems. The likely business impact is local service disruption, not confirmed compromise, based on the available evidence.

Technical view

The flaw is a NULL pointer dereference in spk_ttyio_release after spk_ttyio_initialise_ldisc fails and in_synth->dev was never initialized. The upstream fix adds a guard for in_synth->dev. Evidence points to local denial-of-service conditions around Speakup module lifecycle, not remote exploitation.

Likely exposure

Exposure appears limited to Linux systems running affected kernel versions with Speakup-related modules available or used. Systems without this driver path enabled are less likely to be exposed, but the bundle does not provide distribution-specific package status.

Exploitation context

CISA KEV status is false, and the provided sources do not claim exploitation in the wild. The described trigger came from syzkaller testing on QEMU and involved local module load and removal behavior after failed TTY setup.

Researcher notes

The record lacks CVSS, CWE, and distribution-level affected package details. Research should focus on kernel branch mapping, distro backports, module availability, and whether local users can reach the module lifecycle path in real deployments.

Mitigation direction

  • Update to a Linux kernel build containing the referenced stable fixes.
  • Check your Linux distribution advisory for backported fixes and supported kernel packages.
  • If Speakup is unnecessary, confirm with vendor guidance whether disabling related modules is appropriate.
  • Prioritize systems where untrusted users can influence kernel module loading or console accessibility drivers.

Validation and detection

  • Inventory Linux kernel versions against the affected and fixed ranges in vendor advisories.
  • Verify whether Speakup or speakup_audptr modules are present or operationally required.
  • Confirm the running kernel includes one of the referenced stable commits or a distro backport.
  • Review kernel logs for NULL dereference traces involving spk_ttyio_release or Speakup cleanup.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2022-48870 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
1ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux4f2a81f3a88217e7340b2cab5c0a5ebd0112514c, 4f2a81f3a88217e7340b2cab5c0a5ebd0112514c, 4f2a81f3a88217e7340b2cab5c0a5ebd0112514cunaffected
LinuxLinux5.12, 0, 5.15.90, 6.1.8, 6.2affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.