Public issue detail

Runaway CPU investigation for sshd-auth: timer churn at rep_movs_alternative

sshd-auth is stuck in a likely timer churn loop: 100.00% of sampled CPU passed through rep_movs_alternative, with repeated thread backtraces show 1 thread(s) around 0x00007f371dc9a7d2 in ?? () from target:<path>.

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

Last seen: 2026-06-13 14:10 UTC. Public JSON: /v1/issues/019ebffd-fcdb-7190-8855-011dca04e59d

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: Timer-related syscalls or symbols dominate the sample, which suggests a wakeup timer is firing too aggressively.
  • Thread summary: thread backtraces show 1 thread(s) around 0x00007f371dc9a7d2 in ?? () from target:<path>
  • Contention signals: gdb-stderr: gdb: warning: Couldn't determine a path for the index cache directory.
  • Repeated loop: read -> read -> clock_nanosleep
  • Top syscalls: read x4, write x3, clock_nanosleep x2
  • Package: openssh-server 1:10.3p1-1
  • Kernel: 6.17.10+deb14-amd64
  • Distribution: debian
0x00007f371dc9a7d2 in ?? () from target:<path>
0x00007f371dce7c7a in clock_nanosleep () from target:<path>
0x00007f371dcf35e3 in nanosleep () from target:<path>
0x00005628ea05b2b6 in ?? ()
0x00005628ea0b14a6 in ?? ()
0x00005628ea0b159d in ?? ()
0x00005628ea059b2c in ?? ()
0x00005628ea0481d5 in ?? ()

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 timer churn loop: 100.00% of sampled CPU passed through apparmor_socket_recvmsg, with repeated thread backtraces show 1 thread(s) around 0x00007fa460a9a7d2 in ?? () from target:<path>.

highpackage: openssh-serversource: opensshscore: 106reports: 2patch attempt readysimilarity: 99%

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

Last seen: 2026-06-13 14:05 UTC. Public page: /issues/019dfcf9-7385-7c01-ba59-9fce98cd0a8f. Public JSON: /v1/issues/019dfcf9-7385-7c01-ba59-9fce98cd0a8f

sshd-auth is stuck in a likely timer churn loop: 100.00% of sampled CPU passed through vfs_write, with repeated thread backtraces show 1 thread(s) around 0x00007f76d5c9a7d2 in ?? () from target:<path>.

highpackage: openssh-serversource: opensshscore: 106reports: 2patch attempt readysimilarity: 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: 2026-06-13 14:05 UTC. Public page: /issues/019e2c59-6707-7471-b7b2-5329d3cdd34e. Public JSON: /v1/issues/019e2c59-6707-7471-b7b2-5329d3cdd34e

sshd-auth is stuck in a likely timer churn loop: 50.00% of sampled CPU passed through __mmdrop, with repeated thread backtraces show 1 thread(s) around 0x00007f022069a7d2 in ?? () from target:<path>.

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: 2026-06-13 07:40 UTC. Public page: /issues/019ebeda-74f7-7d32-8db2-b15521aec662. Public JSON: /v1/issues/019ebeda-74f7-7d32-8db2-b15521aec662

sshd-auth is stuck in a likely timer churn loop: 36.29% of sampled CPU passed through __schedule, with repeated thread backtraces show 1 thread(s) around 0x00007fac7249a7d2 in ?? () from target:<path>.

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: 2026-06-08 23:10 UTC. Public page: /issues/019ea8c5-24b9-7863-b730-83081994767c. Public JSON: /v1/issues/019ea8c5-24b9-7863-b730-83081994767c

sshd-auth is stuck in a likely timer churn loop: 100.00% of sampled CPU passed through tcp_push, with repeated thread backtraces show 1 thread(s) around 0x00007f51dfe9a7d2 in ?? () from target:<path>.

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: 2026-06-08 19:13 UTC. Public page: /issues/019ea31a-f962-7293-a0ce-bff12d2d13fa. Public JSON: /v1/issues/019ea31a-f962-7293-a0ce-bff12d2d13fa

sshd-auth is stuck in a likely timer churn loop: 100.00% of sampled CPU passed through unresolved offset, with repeated read x5, write x5, clock_nanosleep x2.

highpackage: openssh-serversource: opensshscore: 106reports: 2similarity: 97%

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

Last seen: 2026-06-12 00:24 UTC. Public page: /issues/019e6016-53b8-76e3-84e2-fdf4c48c1b40. Public JSON: /v1/issues/019e6016-53b8-76e3-84e2-fdf4c48c1b40

Published attempts

No public attempts have been published for this issue yet.