AZL-73647
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-73647.json
- JSON Data
- https://api.osv.dev/v1/vulns/AZL-73647
- Upstream
- Published
- 2025-09-05T18:15:43Z
- Modified
- 2026-04-21T04:33:57Z
- Summary
- CVE-2025-39673 affecting package kernel for versions less than 5.15.200.1-1
- Details
-
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:
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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.
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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.
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- References