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CVE Record

CVE-2022-49018: mptcp: fix sleep in atomic at close time

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix sleep in atomic at close time Matt reported a splat at msk close time: BUG: sleeping function called from invalid context at net/mptcp/protocol.c:2877 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 155, name: packetdrill preempt_count: 201, expected: 0 RCU nest depth: 0, expected: 0 4 locks held by packetdrill/155: #0: ffff888001536990 (&sb->s_type->i_mutex_key#6){+.+.}-{3:3}, at: __sock_release (net/socket.c:650) #1: ffff88800b498130 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_close (net/mptcp/protocol.c:2973) #2: ffff88800b49a130 (sk_lock-AF_INET/1){+.+.}-{0:0}, at: __mptcp_close_ssk (net/mptcp/protocol.c:2363) #3: ffff88800b49a0b0 (slock-AF_INET){+...}-{2:2}, at: __lock_sock_fast (include/net/sock.h:1820) Preemption disabled at: 0x0 CPU: 1 PID: 155 Comm: packetdrill Not tainted 6.1.0-rc5 #365 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4)) __might_resched.cold (kernel/sched/core.c:9891) __mptcp_destroy_sock (include/linux/kernel.h:110) __mptcp_close (net/mptcp/protocol.c:2959) mptcp_subflow_queue_clean (include/net/sock.h:1777) __mptcp_close_ssk (net/mptcp/protocol.c:2363) mptcp_destroy_common (net/mptcp/protocol.c:3170) mptcp_destroy (include/net/sock.h:1495) __mptcp_destroy_sock (net/mptcp/protocol.c:2886) __mptcp_close (net/mptcp/protocol.c:2959) mptcp_close (net/mptcp/protocol.c:2974) inet_release (net/ipv4/af_inet.c:432) __sock_release (net/socket.c:651) sock_close (net/socket.c:1367) __fput (fs/file_table.c:320) task_work_run (kernel/task_work.c:181 (discriminator 1)) exit_to_user_mode_prepare (include/linux/resume_user_mode.h:49) syscall_exit_to_user_mode (kernel/entry/common.c:130) do_syscall_64 (arch/x86/entry/common.c:87) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) We can't call mptcp_close under the 'fast' socket lock variant, replace it with a sock_lock_nested() as the relevant code is already under the listening msk socket lock protection.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel MPTCP bug during connection close. The public record shows a kernel warning caused by sleeping in an invalid atomic context. Business impact is unclear because no CVSS, CWE, or concrete exploit impact is provided. Treat it as a kernel stability issue until your Linux vendor clarifies severity.

Executive priority

Schedule remediation through normal kernel patch cycles unless your environment relies on MPTCP or operates high-risk multi-tenant Linux infrastructure. Escalate if your vendor rates it higher or confirms service-impacting behavior.

Technical view

CVE-2022-49018 fixes an MPTCP close-time locking issue in the Linux kernel. The description shows a BUG splat in net/mptcp/protocol.c when mptcp_close is called under the fast socket lock variant. The fix replaces that path with sock_lock_nested. Public metadata lists Linux kernel versions including 6.0, 6.0.12, and 6.1 as affected, but distro mappings require vendor confirmation.

Likely exposure

Likely limited to systems running affected Linux kernels with Multipath TCP present and reachable through relevant workloads. Containers inherit host-kernel exposure. Exact exposure depends on distribution backports, kernel configuration, and whether MPTCP is enabled or used.

Exploitation context

The source describes a packetdrill-triggered kernel BUG at socket close time. There is no KEV listing and no cited source stating active exploitation. Public sources do not provide exploitability details, privilege requirements, or a confirmed denial-of-service impact.

Researcher notes

Evidence is official but sparse. The CVE record identifies the root cause and fix commits, but provides no CVSS, CWE, exploit status, or complete version-range clarity. Validate affectedness through upstream stable commits and your distribution’s backport history.

Mitigation direction

  • Check your Linux distribution advisory for fixed kernel packages.
  • Update affected kernels to versions containing the referenced stable fixes.
  • Prioritize hosts using MPTCP or running multi-tenant network workloads.
  • If MPTCP is unnecessary, review vendor guidance on reducing exposure.

Validation and detection

  • Inventory Linux kernel versions across servers and appliances.
  • Compare installed kernels with distribution advisories for CVE-2022-49018.
  • Check kernel changelogs for the referenced stable commit fixes.
  • Confirm whether MPTCP is enabled or used on exposed systems.
  • Monitor kernel logs for MPTCP close-time BUG warnings.
Prepared
Confidence
medium
Sources
4

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.

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CVE-2022-49018 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
3Source 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
LinuxLinux30e51b923e436b631e8d5b77fa5e318c6b066dc7, 30e51b923e436b631e8d5b77fa5e318c6b066dc7, b41808bfa049d1bc7ce8ce1ad4d591f7d203ebb9unaffected
LinuxLinux6.0, 0, 6.0.12, 6.1affected
Weakness

CWE details

No CWE listed

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