CVE-2025-39673 (GCVE-0-2025-39673)

Vulnerability from cvelistv5 – Published: 2025-09-05 17:20 – Updated: 2026-05-12 12:06
VLAI?
Title
ppp: fix race conditions in ppp_fill_forward_path
Summary
In the Linux kernel, the following vulnerability has been resolved: ppp: fix race conditions in ppp_fill_forward_path ppp_fill_forward_path() has two race conditions: 1. The ppp->channels list can change between list_empty() and list_first_entry(), as ppp_lock() is not held. If the only channel is deleted in ppp_disconnect_channel(), list_first_entry() may access an empty head or a freed entry, and trigger a panic. 2. pch->chan can be NULL. When ppp_unregister_channel() is called, pch->chan is set to NULL before pch is removed from ppp->channels. Fix these by using a lockless RCU approach: - Use list_first_or_null_rcu() to safely test and access the first list entry. - Convert list modifications on ppp->channels to their RCU variants and add synchronize_net() after removal. - Check for a NULL pch->chan before dereferencing it.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: f6efc675c9dd8d93f826b79ae7e33e03301db609 , < 9a1969fbffc1f1900d92d7594b1b7d8d72ef3dc7 (git)
Affected: f6efc675c9dd8d93f826b79ae7e33e03301db609 , < 0f1630be6fcca3f0c63e4b242ad202e5cde28a40 (git)
Affected: f6efc675c9dd8d93f826b79ae7e33e03301db609 , < ca18d751bcc9faf5b7e82e9fae1223d103928181 (git)
Affected: f6efc675c9dd8d93f826b79ae7e33e03301db609 , < 94731cc551e29511d85aa8dec61a6c071b1f2430 (git)
Affected: f6efc675c9dd8d93f826b79ae7e33e03301db609 , < f97f6475fdcb3c28ff3c55cc4b7bde632119ec08 (git)
Affected: f6efc675c9dd8d93f826b79ae7e33e03301db609 , < 0417adf367a0af11adf7ace849af4638cfb573f7 (git)
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Linux Linux Affected: 5.13
Unaffected: 0 , < 5.13 (semver)
Unaffected: 5.15.190 , ≤ 5.15.* (semver)
Unaffected: 6.1.149 , ≤ 6.1.* (semver)
Unaffected: 6.6.103 , ≤ 6.6.* (semver)
Unaffected: 6.12.44 , ≤ 6.12.* (semver)
Unaffected: 6.16.4 , ≤ 6.16.* (semver)
Unaffected: 6.17 , ≤ * (original_commit_for_fix)
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.