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CVE Record

CVE-2022-49378: sfc: fix considering that all channels have TX queues

In the Linux kernel, the following vulnerability has been resolved: sfc: fix considering that all channels have TX queues Normally, all channels have RX and TX queues, but this is not true if modparam efx_separate_tx_channels=1 is used. In that cases, some channels only have RX queues and others only TX queues (or more preciselly, they have them allocated, but not initialized). Fix efx_channel_has_tx_queues to return the correct value for this case too. Messages shown at probe time before the fix: sfc 0000:03:00.0 ens6f0np0: MC command 0x82 inlen 544 failed rc=-22 (raw=0) arg=0 ------------[ cut here ]------------ netdevice: ens6f0np0: failed to initialise TXQ -1 WARNING: CPU: 1 PID: 626 at drivers/net/ethernet/sfc/ef10.c:2393 efx_ef10_tx_init+0x201/0x300 [sfc] [...] stripped RIP: 0010:efx_ef10_tx_init+0x201/0x300 [sfc] [...] stripped Call Trace: efx_init_tx_queue+0xaa/0xf0 [sfc] efx_start_channels+0x49/0x120 [sfc] efx_start_all+0x1f8/0x430 [sfc] efx_net_open+0x5a/0xe0 [sfc] __dev_open+0xd0/0x190 __dev_change_flags+0x1b3/0x220 dev_change_flags+0x21/0x60 [...] stripped Messages shown at remove time before the fix: sfc 0000:03:00.0 ens6f0np0: failed to flush 10 queues sfc 0000:03:00.0 ens6f0np0: failed to flush queues

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel sfc network driver bug, not a broadly exposed internet-facing flaw. It affects systems using the sfc driver with separate TX channels enabled, where the driver may try to initialize non-existent TX queues and produce warnings or queue flush failures.

Executive priority

Treat this as a targeted operational stability issue for hosts using specific sfc network hardware, not an emergency internet-wide vulnerability. Prioritize kernel updates during normal maintenance unless affected systems show network initialization failures.

Technical view

The sfc driver assumed every channel had TX queues. With efx_separate_tx_channels=1, some channels are RX-only or TX-only. efx_channel_has_tx_queues returned the wrong value, causing TX queue initialization against invalid or uninitialized queues during device open and cleanup.

Likely exposure

Exposure appears limited to Linux systems using the sfc Ethernet driver and the efx_separate_tx_channels=1 module parameter on affected kernel versions listed in the CVE record.

Exploitation context

The bundle provides no evidence of active exploitation, no KEV listing, no CVSS score, and no remote attack path. The described impact is driver initialization and queue cleanup failure under a specific configuration.

Researcher notes

Evidence is narrow: the public description names the faulty sfc queue-detection logic and shows probe/remove failures. It does not provide CVSS, CWE, exploitability analysis, privilege requirements, or a security boundary impact beyond the resolved kernel bug.

Mitigation direction

  • Check vendor or distribution kernel advisories for fixed packages.
  • Update to a kernel containing the referenced stable sfc fixes.
  • Identify whether sfc hardware and efx_separate_tx_channels=1 are used.
  • Avoid changing production driver parameters without vendor guidance.

Validation and detection

  • Check running kernel version against affected versions in the CVE record.
  • Confirm whether the sfc kernel module is loaded.
  • Review module parameters for efx_separate_tx_channels=1.
  • Inspect boot or kernel logs for TXQ initialization or queue flush failures.
Prepared
Confidence
medium
Sources
7

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

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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
0ADP providers
6Source links

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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux8700aff089843399f95bc7701ae87b642b35a716, 8700aff089843399f95bc7701ae87b642b35a716, 8700aff089843399f95bc7701ae87b642b35a716, 8700aff089843399f95bc7701ae87b642b35a716, 8700aff089843399f95bc7701ae87b642b35a716unaffected
LinuxLinux5.5, 0, 5.10.122, 5.15.47, 5.17.15, 5.18.4, 5.19affected
Weakness

CWE details

No CWE listed

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