Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: net: fix fanout UAF in packet_release() via NETDEV_UP race `packet_release()` has a race window where `NETDEV_UP` can re-register a socket into a fanout group's `arr[]` array. The re-registration is not cleaned up by `fanout_release()`, leaving a dangling pointer in the fanout array. `packet_release()` does NOT zero `po->num` in its `bind_lock` section. After releasing `bind_lock`, `po->num` is still non-zero and `po->ifindex` still matches the bound device. A concurrent `packet_notifier(NETDEV_UP)` that already found the socket in `sklist` can re-register the hook. For fanout sockets, this re-registration calls `__fanout_link(sk, po)` which adds the socket back into `f->arr[]` and increments `f->num_members`, but does NOT increment `f->sk_ref`. The fix sets `po->num` to zero in `packet_release` while `bind_lock` is held to prevent NETDEV_UP from linking, preventing the race window. This bug was found following an additional audit with Claude Code based on CVE-2025-38617.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before ee642b1962caa9aa231c01abbd58bc453ae6b66e; affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before 42cfd7898eeed290c9fb73f732af1f7d6b0a703e; affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before 1b4c03f8892d955385c202009af7485364731bb9; affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before 654386baef228c2992dbf604c819e4c7c35fc71b; affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before 75fe6db23705a1d55160081f7b37db9665b1880b; affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before d0c7cdc15fdf8c4f91aca1928e52295d175b6ec6; affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before ceccbfc6de720ad633519a226715989cfb065af1; affected ce06b03e60fc19c680d1bf873e779bf11c2fc518 before 42156f93d123436f2a27c468f18c966b7e5db796 |
| Linux / Linux | affected 3.1; unaffected 0 before 3.1; unaffected 5.10.253 through 5.10.*; unaffected 5.15.203 through 5.15.*; unaffected 6.1.168 through 6.1.*; unaffected 6.6.131 through 6.6.*; unaffected 6.12.80 through 6.12.*; unaffected 6.18.21 through 6.18.*; unaffected 6.19.11 through 6.19.*; unaffected 7.0 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/ee642b1962caa9aa231c01abbd58bc453ae6b66e
- https://git.kernel.org/stable/c/42cfd7898eeed290c9fb73f732af1f7d6b0a703e
- https://git.kernel.org/stable/c/1b4c03f8892d955385c202009af7485364731bb9
- https://git.kernel.org/stable/c/654386baef228c2992dbf604c819e4c7c35fc71b
- https://git.kernel.org/stable/c/75fe6db23705a1d55160081f7b37db9665b1880b
- https://git.kernel.org/stable/c/d0c7cdc15fdf8c4f91aca1928e52295d175b6ec6
- https://git.kernel.org/stable/c/ceccbfc6de720ad633519a226715989cfb065af1
- https://git.kernel.org/stable/c/42156f93d123436f2a27c468f18c966b7e5db796
ADP enrichment
No English description supplied.
No English description supplied.
No references supplied.