EUVD-2026-12886
Lifecycle Timeline
4Description
In the Linux kernel, the following vulnerability has been resolved: net: add proper RCU protection to /proc/net/ptype Yin Fengwei reported an RCU stall in ptype_seq_show() and provided a patch. Real issue is that ptype_seq_next() and ptype_seq_show() violate RCU rules. ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev to get device name without any barrier. At the same time, concurrent writers can remove a packet_type structure (which is correctly freed after an RCU grace period) and clear pt->dev without an RCU grace period. Define ptype_iter_state to carry a dev pointer along seq_net_private: struct ptype_iter_state { struct seq_net_private p; struct net_device *dev; // added in this patch }; We need to record the device pointer in ptype_get_idx() and ptype_seq_next() so that ptype_seq_show() is safe against concurrent pt->dev changes. We also need to add full RCU protection in ptype_seq_next(). (Missing READ_ONCE() when reading list.next values) Many thanks to Dong Chenchen for providing a repro.
Analysis
A race condition vulnerability exists in the Linux kernel's /proc/net/ptype implementation where concurrent readers and writers violate RCU (Read-Copy-Update) synchronization rules, allowing information disclosure through unsafe access to device pointers. The vulnerability affects all Linux kernel versions with the vulnerable ptype_seq_show() and ptype_seq_next() functions. …
Sign in for full analysis, threat intelligence, and remediation guidance.
Priority Score
Vendor Status
Debian
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | vulnerable | 5.10.223-1 | - |
| bullseye (security) | vulnerable | 5.10.251-1 | - |
| bookworm | vulnerable | 6.1.159-1 | - |
| bookworm (security) | vulnerable | 6.1.164-1 | - |
| trixie | vulnerable | 6.12.73-1 | - |
| trixie (security) | vulnerable | 6.12.74-2 | - |
| forky | fixed | 6.19.6-2 | - |
| sid | fixed | 6.19.8-1 | - |
| (unstable) | fixed | 6.18.10-1 | - |
Share
External POC / Exploit Code
Leaving vuln.today