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CVE Record

CVE-2022-48994: ALSA: seq: Fix function prototype mismatch in snd_seq_expand_var_event

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix function prototype mismatch in snd_seq_expand_var_event With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. seq_copy_in_user() and seq_copy_in_kernel() did not have prototypes matching snd_seq_dump_func_t. Adjust this and remove the casts. There are not resulting binary output differences. This was found as a result of Clang's new -Wcast-function-type-strict flag, which is more sensitive than the simpler -Wcast-function-type, which only checks for type width mismatches.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue is a reliability bug in the ALSA sequencer path. On kernels built with Clang kernel CFI, a function prototype mismatch can trigger a runtime CFI failure, causing a kernel panic or killing the calling thread. The provided sources do not show active exploitation or a CVSS score.

Executive priority

Treat this as a kernel maintenance item unless local context shows kCFI-enabled kernels with active ALSA sequencer use. There is no sourced evidence of active exploitation, but kernel panics can still create business disruption on exposed systems.

Technical view

snd_seq_expand_var_event used callbacks whose prototypes did not exactly match snd_seq_dump_func_t. With CONFIG_CFI_CLANG, indirect-call prototype validation can reject that target at runtime. The Linux fix aligns seq_copy_in_user and seq_copy_in_kernel with the expected prototype and removes casts, with no stated binary output difference.

Likely exposure

Exposure is limited to Linux systems running affected kernel versions where the ALSA sequencer path is present and Clang kCFI is enabled. The CVE record lists Linux kernel versions and stable-series fixes, but distro-specific exposure depends on vendor backports and kernel configuration.

Exploitation context

The bundle states this was found through Clang’s stricter function-cast warning. KEV is false, and no supplied source claims public exploitation. The plausible impact described is availability loss through kernel panic or thread termination, not confirmed remote compromise.

Researcher notes

The record lacks CVSS, CWE, and exploit evidence. Analysis should focus on kernel configuration, ALSA sequencer reachability, and whether the specific stable fix was backported. Avoid assuming all Linux deployments are equally exposed.

Mitigation direction

  • Apply the relevant Linux stable kernel update or distro kernel package.
  • Check vendor advisories for backported fixes before assuming version numbers are vulnerable.
  • Prioritize systems using CONFIG_CFI_CLANG and ALSA sequencer functionality.
  • Track the referenced stable commits for branch-specific remediation status.

Validation and detection

  • Inventory Linux kernel versions across servers, endpoints, and appliances.
  • Confirm whether kernels are built with CONFIG_CFI_CLANG enabled.
  • Check whether ALSA sequencer support is present or loaded.
  • Map installed kernel packages to vendor advisories or referenced stable commits.
Prepared
Confidence
high
Sources
10

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

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CVE-2022-48994 mapping review

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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
9Source 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
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2unaffected
LinuxLinux2.6.12, 0, 4.9.336, 4.14.302, 4.19.269, 5.4.227, 5.10.159, 5.15.83, 6.0.13, 6.1affected
Weakness

CWE details

No CWE listed

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