Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.23% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2024
CVE-2022-48721High confidence
net/smc: Forward wakeup to smc socket waitqueue after fallback
Linux · Linux
7.8HighCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productHigh technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Medium, lowered one band.downgradedsince 5 Aug 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Linux Linux and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Canonical Ubuntu Security: 1 affected package state with no published fix
Distribution package intelligence
5 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Package result overrides the generic status
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 1 affected package state shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.16.10-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.16.10-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.16.10-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.16.10-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-raspi-realtime | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
In the Linux kernel, the following vulnerability has been resolved: net/smc: Forward wakeup to smc socket waitqueue after fallback When we replace TCP with SMC and a fallback occurs, there may be some socket waitqueue entries remaining in smc socket->wq, such as eppoll_entries inserted by userspace applications. After the fallback, data flows over TCP/IP and only clcsocket->wq will be woken up. Applications can't be notified by the entries which were inserted in smc socket->wq before fallback. So we need a mechanism to wake up smc socket->wq at the same time if some entries remaining in it. The current workaround is to transfer the entries from smc socket->wq to clcsock->wq during the fallback. But this may cause a crash like this: general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Tainted: G E 5.16.0+ #107 RIP: 0010:__wake_up_common+0x65/0x170 Call Trace: <IRQ> __wake_up_common_lock+0x7a/0xc0 sock_def_readable+0x3c/0x70 tcp_data_queue+0x4a7/0xc40 tcp_rcv_established+0x32f/0x660 ? sk_filter_trim_cap+0xcb/0x2e0 tcp_v4_do_rcv+0x10b/0x260 tcp_v4_rcv+0xd2a/0xde0 ip_protocol_deliver_rcu+0x3b/0x1d0 ip_local_deliver_finish+0x54/0x60 ip_local_deliver+0x6a/0x110 ? tcp_v4_early_demux+0xa2/0x140 ? tcp_v4_early_demux+0x10d/0x140 ip_sublist_rcv_finish+0x49/0x60 ip_sublist_rcv+0x19d/0x230 ip_list_rcv+0x13e/0x170 __netif_receive_skb_list_core+0x1c2/0x240 netif_receive_skb_list_internal+0x1e6/0x320 napi_complete_done+0x11d/0x190 mlx5e_napi_poll+0x163/0x6b0 [mlx5_core] __napi_poll+0x3c/0x1b0 net_rx_action+0x27c/0x300 __do_softirq+0x114/0x2d2 irq_exit_rcu+0xb4/0xe0 common_interrupt+0xba/0xe0 </IRQ> <TASK> The crash is caused by privately transferring waitqueue entries from smc socket->wq to clcsock->wq. The owners of these entries, such as epoll, have no idea that the entries have been transferred to a different socket wait queue and still use original waitqueue spinlock (smc socket->wq.wait.lock) to make the entries operation exclusive, but it doesn't work. The operations to the entries, such as removing from the waitqueue (now is clcsock->wq after fallback), may cause a crash when clcsock waitqueue is being iterated over at the moment. This patch tries to fix this by no longer transferring wait queue entries privately, but introducing own implementations of clcsock's callback functions in fallback situation. The callback functions will forward the wakeup to smc socket->wq if clcsock->wq is actually woken up and smc socket->wq has remaining entries.
What
In the Linux kernel, the following vulnerability has been resolved: net/smc: Forward wakeup to smc socket waitqueue after fallback When we replace TCP with SMC and a fallback occurs, there may be some socket waitqueue entries remaining in smc socket->wq, such as eppoll_entries inserted by userspace applications. After the fallback, data flows over TCP/IP and only clcsocket->wq will be woken up. Applications can't be notified by the entries which were inserted in smc socket->wq before fallback. So we need a mechanism to wake up smc socket->wq at the same time if some entries remaining in it. The current workaround is to transfer the entries from smc socket->wq to clcsock->wq during the fallback. But this may cause a crash like this: general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Tainted: G E 5.16.0+ #107 RIP: 0010:__wake_up_common+0x65/0x170 Call Trace: <IRQ> __wake_up_common_lock+0x7a/0xc0 sock_def_readable+0x3c/0x70 tcp_data_queue+0x4a7/0xc40 tcp_rcv_established+0x32f/0x660 ? sk_filter_trim_cap+0xcb/0x2e0 tcp_v4_do_rcv+0x10b/0x260 tcp_v4_rcv+0xd2a/0xde0 ip_protocol_deliver_rcu+0x3b/0x1d0 ip_local_deliver_finish+0x54/0x60 ip_local_deliver+0x6a/0x110 ? tcp_v4_early_demux+0xa2/0x140 ? tcp_v4_early_demux+0x10d/0x140 ip_sublist_rcv_finish+0x49/0x60 ip_sublist_rcv+0x19d/0x230 ip_list_rcv+0x13e/0x170 __netif_receive_skb_list_core+0x1c2/0x240 netif_receive_skb_list_internal+0x1e6/0x320 napi_complete_done+0x11d/0x190 mlx5e_napi_poll+0x163/0x6b0 [mlx5_core] __napi_poll+0x3c/0x1b0 net_rx_action+0x27c/0x300 __do_softirq+0x114/0x2d2 irq_exit_rcu+0xb4/0xe0 common_interrupt+0xba/0xe0 </IRQ> <TASK> The crash is caused by privately transferring waitqueue entries from smc socket->wq to clcsock->wq. The owners of these entries, such as epoll, have no idea that the entries have been transferred to a different socket wait queue and still use original waitqueue spinlock (smc socket->wq.wait.lock) to make the entries operation exclusive, but it doesn't work. The operations to the entries, such as removing from the waitqueue (now is clcsock->wq after fallback), may cause a crash when clcsock waitqueue is being iterated over at the moment. This patch tries to fix this by no longer transferring wait queue entries privately, but introducing own implementations of clcsock's callback functions in fallback situation. The callback functions will forward the wakeup to smc socket->wq if clcsock->wq is actually woken up and smc socket->wq has remaining entries.
Why
The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.
What
In the Linux kernel, the following vulnerability has been resolved: net/smc: Forward wakeup to smc socket waitqueue after fallback When we replace TCP with SMC and a fallback occurs, there may be some socket waitqueue entries remaining in smc socket->wq, such as eppoll_entries inserted by userspace applications. After the fallback, data flows over TCP/IP and only clcsocket->wq will be woken up. Applications can't be notified by the entries which were inserted in smc socket->wq before fallback. So we need a mechanism to wake up smc socket->wq at the same time if some entries remaining in it. The current workaround is to transfer the entries from smc socket->wq to clcsock->wq during the fallback. But this may cause a crash like this: general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 0 Comm: swapper/3 Kdump: loaded Tainted: G E 5.16.0+ #107 RIP: 0010:__wake_up_common+0x65/0x170 Call Trace: <IRQ> __wake_up_common_lock+0x7a/0xc0 sock_def_readable+0x3c/0x70 tcp_data_queue+0x4a7/0xc40 tcp_rcv_established+0x32f/0x660 ? sk_filter_trim_cap+0xcb/0x2e0 tcp_v4_do_rcv+0x10b/0x260 tcp_v4_rcv+0xd2a/0xde0 ip_protocol_deliver_rcu+0x3b/0x1d0 ip_local_deliver_finish+0x54/0x60 ip_local_deliver+0x6a/0x110 ? tcp_v4_early_demux+0xa2/0x140 ? tcp_v4_early_demux+0x10d/0x140 ip_sublist_rcv_finish+0x49/0x60 ip_sublist_rcv+0x19d/0x230 ip_list_rcv+0x13e/0x170 __netif_receive_skb_list_core+0x1c2/0x240 netif_receive_skb_list_internal+0x1e6/0x320 napi_complete_done+0x11d/0x190 mlx5e_napi_poll+0x163/0x6b0 [mlx5_core] __napi_poll+0x3c/0x1b0 net_rx_action+0x27c/0x300 __do_softirq+0x114/0x2d2 irq_exit_rcu+0xb4/0xe0 common_interrupt+0xba/0xe0 </IRQ> <TASK> The crash is caused by privately transferring waitqueue entries from smc socket->wq to clcsock->wq. The owners of these entries, such as epoll, have no idea that the entries have been transferred to a different socket wait queue and still use original waitqueue spinlock (smc socket->wq.wait.lock) to make the entries operation exclusive, but it doesn't work. The operations to the entries, such as removing from the waitqueue (now is clcsock->wq after fallback), may cause a crash when clcsock waitqueue is being iterated over at the moment. This patch tries to fix this by no longer transferring wait queue entries privately, but introducing own implementations of clcsock's callback functions in fallback situation. The callback functions will forward the wakeup to smc socket->wq if clcsock->wq is actually woken up and smc socket->wq has remaining entries.
Why
The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- local access → vulnerable operation → disrupt the affected service
- Attack surface
- Local
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration. - CWE not yet assigned
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix availability varies by product
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 20 Jun 2024 · Last source change 5 Aug 2026, 08:51 UTC · CWE not yet assigned
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2022-53600
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceUnavailable
NVD statusNVD modified after enrichment
Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.