CVE-2025-37747perf: Fix hang while freeing sigtrap event

Description

In the Linux kernel, the following vulnerability has been resolved: perf: Fix hang while freeing sigtrap event Perf can hang while freeing a sigtrap event if a related deferred signal hadn't managed to be sent before the file got closed: perf_event_overflow() task_work_add(perf_pending_task) fput() task_work_add(____fput()) task_work_run() ____fput() perf_release() perf_event_release_kernel() _free_event() perf_pending_task_sync() task_work_cancel() -> FAILED rcuwait_wait_event() Once task_work_run() is running, the list of pending callbacks is removed from the task_struct and from this point on task_work_cancel() can't remove any pending and not yet started work items, hence the task_work_cancel() failure and the hang on rcuwait_wait_event(). Task work could be changed to remove one work at a time, so a work running on the current task can always cancel a pending one, however the wait / wake design is still subject to inverted dependencies when remote targets are involved, as pictured by Oleg: T1 T2 fd = perf_event_open(pid => T2->pid); fd = perf_event_open(pid => T1->pid); close(fd) close(fd) <IRQ> <IRQ> perf_event_overflow() perf_event_overflow() task_work_add(perf_pending_task) task_work_add(perf_pending_task) </IRQ> </IRQ> fput() fput() task_work_add(____fput()) task_work_add(____fput()) task_work_run() task_work_run() ____fput() ____fput() perf_release() perf_release() perf_event_release_kernel() perf_event_release_kernel() _free_event() _free_event() perf_pending_task_sync() perf_pending_task_sync() rcuwait_wait_event() rcuwait_wait_event() Therefore the only option left is to acquire the event reference count upon queueing the perf task work and release it from the task work, just like it was done before 3a5465418f5f ("perf: Fix event leak upon exec and file release") but without the leaks it fixed. Some adjustments are necessary to make it work: * A child event might dereference its parent upon freeing. Care must be taken to release the parent last. * Some places assuming the event doesn't have any reference held and therefore can be freed right away must instead put the reference and let the reference counting to its job.

Timeline

Scores

EPSS (exploitation in 30 days)

0.25% · top 84% of all CVEs (14 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.

Affected products

• Linux · Linux

  • affected ed2c202dac55423a52d7e2290f2888bf08b8ee99 – < 20ab73bb467d900662dca043452aadecb2db8338
  • affected 104e258a004037bc7dba9f6085c71dad6af57ad4 – < aae58a39ac4c63c3fa53536fb2504c9f1d0e1719
  • affected 3a5465418f5fd970e86a86c7f4075be262682840 – < fa1827fa968c0674e9b6fca223fa9fb4da4493eb
  • affected 3a5465418f5fd970e86a86c7f4075be262682840 – < 665b87b8f8b3aeb49083ef3b65c4953e7753fc12
  • affected 3a5465418f5fd970e86a86c7f4075be262682840 – < 1267bd38f161c1a27d9b722de017027167a225a0
  • affected 3a5465418f5fd970e86a86c7f4075be262682840 – < 56799bc035658738f362acec3e7647bb84e68933
  • affected 9ad46f1fef421d43cdab3a7d1744b2f43b54dae0
  • affected f34d8307a73a18de5320fcc6f40403146d061891
  • affected 6.1.103 – < 6.1.191
  • affected 6.6.44 – < 6.6.160
  • affected 5.15.165 – < 5.16
  • affected 6.10.3 – < 6.11

• Linux · Linux

  • affected 6.11
  • unaffected < 6.11
  • unaffected 6.1.191 – ≤ 6.1.*
  • unaffected 6.6.160 – ≤ 6.6.*
  • unaffected 6.12.24 – ≤ 6.12.*
  • unaffected 6.13.12 – ≤ 6.13.*
  • unaffected 6.14.3 – ≤ 6.14.*
  • unaffected 6.15 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2025-13078 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2025-37747](https://cveledger.app/badge/CVE-2025-37747.svg)](https://cveledger.app/cve/CVE-2025-37747)

Record last updated 5 Nov 2026, 20:41 UTC.