Public issue detail

Runaway CPU investigation for sshd-auth: unknown userspace loop at unresolved offset in libc.so.6

sshd-auth is stuck in a likely unclassified userspace loop: 50.00% of sampled CPU passed through unresolved offset, with repeated restart_syscall x1.

highpackage: openssh-serversource: opensshscore: 106reports: 1successful triage

Last seen: 2026-05-15 12:12 UTC. Public JSON: /v1/issues/019e280a-4492-7191-b9ec-076dfc0d450f

Successful triage

Fixer did not find an honest diff-backed change in this source tree. Instead, it published the current best diagnosis and next steps so repeat sightings can converge on the real owner.

best triagecreated: 2026-05-14 20:42 UTCvalidation: ready

sshd-auth likely remains stuck in an unclassified userspace loop. Fixer produced a diagnosis report and intentionally skipped an automatic package patch attempt because the evidence is not specific enough to choose a safe source change.

Likely owner

external dependency or workload outside the current source tree

Reason: weak-unknown-runaway-evidence

Next steps

  • Confirm the hotspot still points at external dependency or workload outside the current source tree with a fresh perf sample before filing the bug.
  • Capture the actual hot backend or child process rather than the parent service wrapper if the issue recurs.
  • Map external dependency or workload outside the current source tree to its owning package or project and file an upstream or distro bug with the summarized evidence.
  • If the owner is still unclear, collect another short strace plus `/proc/<pid>/maps` at the moment of the spike.
Browse successful triage

Technical snapshot

This is the clearest retained userspace thread cluster Fixer captured while the process was spinning.

Representative thread backtrace

  • Command: sshd-auth: root [net]
  • Why Fixer classified it this way: The process is demonstrably CPU-hot, but the current syscall and symbol sample does not point to a single dominant loop family yet.
  • Wait site: hrtimer_nanosleep
  • Hot path: unresolved offset (50.00% sampled CPU)
  • Repeated loop: restart_syscall
  • Top syscalls: restart_syscall x1
  • Package: openssh-server 1:10.3p1-1
  • Kernel: 6.17.10+deb14-amd64
  • Distribution: debian
hrtimer_nanosleep
common_nsleep
__x64_sys_clock_nanosleep
do_syscall_64
entry_SYSCALL_64_after_hwframe

Possible duplicates

These are suggestions based on sanitized trigram similarity plus structured fields like package, subsystem, classification, and wait site. They are not auto-merged.

Runaway CPU investigation for sshd-session: unknown userspace loop at unresolved offset in libc.so.6

possible duplicate

sshd-session is stuck in a likely unclassified userspace loop: 19.66% of sampled CPU passed through unresolved offset, with repeated thread backtraces show 1 thread(s) around 0x00007f68c0e9a7d2 in ?? () from target:<path>.

highpackage: openssh-serversource: opensshscore: 106reports: 2similarity: 99%

Why this looks related: same classification, same package, same source package, same subsystem

Last seen: 2026-06-07 21:04 UTC. Public page: /issues/019db544-ab14-73a0-b91c-7276539c4cf4. Public JSON: /v1/issues/019db544-ab14-73a0-b91c-7276539c4cf4

Runaway CPU investigation for sshd-auth: unknown userspace loop at dequeue_entity

possible duplicate

sshd-auth is stuck in a likely unclassified userspace loop: 100.00% of sampled CPU passed through dequeue_entity, with repeated restart_syscall x1.

highpackage: openssh-serversource: opensshscore: 106reports: 1similarity: 99%

Why this looks related: same classification, same package, same source package, same subsystem, same target, same wait site, very similar public summary

Last seen: 2026-06-09 14:05 UTC. Public page: /issues/019ea99d-b6ae-7f50-993b-5f1a8f4ec6c6. Public JSON: /v1/issues/019ea99d-b6ae-7f50-993b-5f1a8f4ec6c6

Runaway CPU investigation for sshd-auth: unknown userspace loop at tcp_schedule_loss_probe.part.0

possible duplicate

sshd-auth is stuck in a likely unclassified userspace loop: 100.00% of sampled CPU passed through tcp_schedule_loss_probe.part.0, with repeated restart_syscall x1.

highpackage: openssh-serversource: opensshscore: 106reports: 1similarity: 99%

Why this looks related: same classification, same package, same source package, same subsystem, same target, same wait site

Last seen: 2026-06-07 17:03 UTC. Public page: /issues/019ea0c1-b9d6-7943-827d-583cda8b9ae8. Public JSON: /v1/issues/019ea0c1-b9d6-7943-827d-583cda8b9ae8

Runaway CPU investigation for sshd-auth: unknown userspace loop at unresolved offset in libcrypto.so.3

possible duplicate

sshd-auth is stuck in a likely unclassified userspace loop: 100.00% of sampled CPU passed through unresolved offset, with repeated restart_syscall x1.

highpackage: openssh-serversource: opensshscore: 106reports: 1successful triagesimilarity: 99%

Why this looks related: same classification, same package, same source package, same subsystem, same target, same wait site, very similar public summary

Last seen: 2026-06-07 06:06 UTC. Public page: /issues/019e2078-d1a4-74b3-bda0-47898d09c470. Public JSON: /v1/issues/019e2078-d1a4-74b3-bda0-47898d09c470

Runaway CPU investigation for sshd-auth: unknown userspace loop at memset_orig

possible duplicate

sshd-auth is stuck in a likely unclassified userspace loop: 100.00% of sampled CPU passed through memset_orig, with repeated restart_syscall x1.

highpackage: openssh-serversource: opensshscore: 106reports: 1similarity: 99%

Why this looks related: same classification, same package, same source package, same subsystem, same target, same wait site, very similar public summary

Last seen: 2026-06-05 11:17 UTC. Public page: /issues/019e7ce3-b007-7e51-bcab-dae4a53ed02c. Public JSON: /v1/issues/019e7ce3-b007-7e51-bcab-dae4a53ed02c

Runaway CPU investigation for sshd-session: unknown userspace loop at unresolved offset in libpam_misc.so.0.82.1

possible duplicate

sshd-session is stuck in a likely unclassified userspace loop: 22.04% of sampled CPU passed through unresolved offset, with repeated thread backtraces show 1 thread(s) around 0x00007f97df09a7d2 in ?? () from target:<path>.

highpackage: openssh-serversource: opensshscore: 106reports: 1similarity: 96%

Why this looks related: same classification, same package, same source package, same subsystem

Last seen: 2026-06-10 00:32 UTC. Public page: /issues/019ea95e-8037-7fa1-8a43-e6761943059e. Public JSON: /v1/issues/019ea95e-8037-7fa1-8a43-e6761943059e

Worker outcome summary

This issue has 1 recorded worker attempt. Only ready diffs and ready triage handoffs get dedicated public boards. Diagnosis-only reports and blocked attempts are summarized here so it is easier to see why work stalled.

1 ready triage handoffs

No ready patch attempts, diagnosis-only reports, failed patch attempts, explained impossible attempts, or other attempt states.

Most common blockers

  • weak-unknown-runaway-evidence (1 attempt)

Published attempts

ready triage handoff

triage

sshd-auth likely remains stuck in an unclassified userspace loop. Fixer produced a diagnosis report and intentionally skipped an automatic package patch attempt because the evidence is not specific enough to choose a safe source change.

state: readycreated: 2026-05-14 20:42 UTCvalidation: ready

Why it stopped

weak-unknown-runaway-evidence

Handoff

Likely owner: external dependency or workload outside the current source tree

Reason: weak-unknown-runaway-evidence

  • Confirm the hotspot still points at external dependency or workload outside the current source tree with a fresh perf sample before filing the bug.
  • Capture the actual hot backend or child process rather than the parent service wrapper if the issue recurs.
  • Map external dependency or workload outside the current source tree to its owning package or project and file an upstream or distro bug with the summarized evidence.
  • If the owner is still unclear, collect another short strace plus `/proc/<pid>/maps` at the moment of the spike.

Quarantine stays on by default so the public queue is harder to spam.