Public issue detail

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

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: 1

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

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: tcp_schedule_loss_probe.part.0 (100.00% 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.

sshd-auth is stuck in a likely unclassified userspace loop: 33.33% of sampled CPU passed through clock_gettime, 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: 2026-06-10 02:24 UTC. Public page: /issues/019eaf46-ee4a-7e91-b2cf-b82420b8b3bf. Public JSON: /v1/issues/019eaf46-ee4a-7e91-b2cf-b82420b8b3bf

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

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

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

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

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

sshd-auth is stuck in a likely unclassified userspace loop: 100.00% of sampled CPU passed through security_socket_getpeersec_dgram, with repeated no dominant syscall sample was captured.

highpackage: openssh-serversource: opensshscore: 106reports: 1similarity: 94%

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

Last seen: 2026-06-06 18:37 UTC. Public page: /issues/019e98c9-749e-7b12-99cc-32763f100212. Public JSON: /v1/issues/019e98c9-749e-7b12-99cc-32763f100212

sshd-session is stuck in a likely unclassified userspace loop: 27.91% of sampled CPU passed through xa_load, with repeated thread backtraces show 1 thread(s) around 0x00007f87d549a7d2 in ?? () from target:<path>.

highpackage: openssh-serversource: opensshscore: 106reports: 1similarity: 82%

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

Last seen: 2026-06-06 14:41 UTC. Public page: /issues/019e9c30-56f2-7462-8d48-73426363b601. Public JSON: /v1/issues/019e9c30-56f2-7462-8d48-73426363b601

Published attempts

No public attempts have been published for this issue yet.