In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix call timer start racing with call destruction The rxrpc_call struct has a timer used to handle various timed events relating to a call
Why It Matters
Analysis dossierWhy It Matters
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix call timer start racing with call destruction The rxrpc_call struct has a timer used to handle various timed events relating to a call. This timer can get started from the packet input routines that are run in softirq mode with just the RCU read lock held. Unfortunately, because only the RCU read lock is held - and neither ref or other lock is taken - the call can start getting destroyed at the same time a packet comes in addressed to that call. This causes the timer - which was already stopped - to get restarted. Later, the timer dispatch code may then oops if the timer got deallocated first. Fix this by trying to take a ref on the rxrpc_call struct and, if successful, passing that ref along to the timer. If the timer was already running, the ref is discarded. The timer completion routine can then pass the ref along to the call's work item when it queues it. If the timer or work item where already queued/running, the extra ref is discarded.
High Severity / Review
Unknown
Unknown
Risk basis: SOC ecosystem technology relevance; CRITICAL severity; Critical CVSS without confirmed KEV exploitation
Affected Products & Remediation
1 source-backed product- linux linux kernel · >= 4.15.1 < 5.10.110; >= 5.11 < 5.15.33; >= 5.16 < 5.16.19; >= 5.17 < 5.17.2; 4.15 · NVD CPE · Source
Vendor or catalog guidance (source)
Not provided by source
Known exploitation (source facts)
Only what a source states. Unknown means no source has said either way; it is not "not exploited".
- CISA KEV
- Unknown
- Exploited (source statement)
- Unknown
- Publicly disclosed (source)
- Unknown
Suggested hunting (rule-based inference)
SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.
Matched network-unauthenticated (CVSS AV:N, CVSS PR:N, CVSS UI:N)
Exposure
- Identify devices reporting this CVE and note which expose the affected service to untrusted networks.Telemetry: DeviceTvmSoftwareVulnerabilities · A network-reachable, no-privilege vector makes internet-facing instances the first exposure question. · Rule network-unauthenticated
Exploitation evidence
- Review inbound connections to the affected service from unexpected sources since the advisory date.Telemetry: DeviceNetworkEvents · Hunting hypothesis from the CVSS vector; it does not show that exploitation occurred. · Rule network-unauthenticated
Response
- Confirm the source-stated update is installed and the CVE is no longer reported.Telemetry: DeviceTvmSoftwareVulnerabilities · A follow-up inventory check verifies remediation. · Rule network-unauthenticated
CISA KEV Record
CISA KEV status was not determined for this record.
Change History & Source Data
— No recorded material change
- CNA / source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- Record status · verification
- UPDATED · NVD API
- CPE
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:-:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc2:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc3:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc4:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc5:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc6:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc7:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc8:*:*:*:*:*:*, cpe:2.3:o:linux:linux_kernel:4.15:rc9:*:*:*:*:*:*
Evidence & Provenance
— No published hunting query names this record. Browse community and library queries instead.
Correlated briefings
— No published briefing references this CVE