af_unix: Unlink scc_entry in unix_del_edge().
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.1.189, 6.6.158, 6.12.111, 6.18.53, 7.1.10
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: af_unix: Unlink scc_entry in unix_del_edge(). Kyle Zeng reported that GC could free a dead SCC partially. The scenario is as follows: 1) Create two SCCs: X -. A <-> B ^--' 2) Run the following concurrently: 2-1) send() sk-B to sk-B from sk-X 2-2) close() both A and B At 2-1), there is a small window where unix_add_edges() publishes a new edge (B <-> B) to GC but its skb is not queued by skb_queue_tail(). If 2-2) completes before skb_queue_tail() and GC is triggered, it judges A <-> B as dead, but B is not freed because GC cannot collect the not-yet-queued skb holding the B <-> B edge. X -. A <-> B -. This edge is visible ^--' ^..' but skb is not This itself is not a problem since the next GC run will judge B as dead as well and free it finally. X -. A <.> B -. ^--' ^--' However, X's SCC forces the next GC to call unix_walk_scc_fast(), and it iterates over A through B's scc_entry. Let's unlink scc_entry before freeing the vertex in unix_del_edge().
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 5dfd283f4651d04dbb70ceb9ae5c4a30eda3c52a · fixed in 2b6c2842692d08e7acaf32d1eb47f95def35f3fe; From de7921631ff323369aa63a4324695ab54ea4047e · fixed in 6fda5c51b8e43a8440f76e65c89d9f95ddb2ef33; From 4090fa373f0e763c43610853d2774b5979915959 · fixed in 1293fd69a50d188a5788b08ba3741a3e86be1608; From 4090fa373f0e763c43610853d2774b5979915959 · fixed in fe198b077864feafd4aa4b33b1a5ce26f50195a2; From 4090fa373f0e763c43610853d2774b5979915959 · fixed in e3702470ced94fad74d71e2232f022d2eb752a6d; From 4090fa373f0e763c43610853d2774b5979915959 · fixed in 594d905195024b228c962627ae5ae7c17bd582a4; From 6.1.141 · fixed in 6.1.189; From 6.6.93 · fixed in 6.6.158
- Linux Linux
6.10
- KernelLinux
fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.111; From 6.10.0 · fixed in 6.18.53; From 6.13.0 · fixed in 7.1.10