net/handshake: duplicate handshake cancellations leak socket
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.6.120, 6.12.64, 6.18.3
- 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
- Exploitation: none
- Automatable: yes
- Technical impact: total
Summary
In the Linux kernel, the following vulnerability has been resolved: net/handshake: duplicate handshake cancellations leak socket When a handshake request is cancelled it is removed from the handshake_net->hn_requests list, but it is still present in the handshake_rhashtbl until it is destroyed. If a second cancellation request arrives for the same handshake request, then remove_pending() will return false... and assuming HANDSHAKE_F_REQ_COMPLETED isn't set in req->hr_flags, we'll continue processing through the out_true label, where we put another reference on the sock and a refcount underflow occurs. This can happen for example if a handshake times out - particularly if the SUNRPC client sends the AUTH_TLS probe to the server but doesn't follow it up with the ClientHello due to a problem with tlshd. When the timeout is hit on the server, the server will send a FIN, which triggers a cancellation request via xs_reset_transport(). When the timeout is hit on the client, another cancellation request happens via xs_tls_handshake_sync(). Add a test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED) in the pending cancel path so duplicate cancels can be detected.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 3b3009ea8abb713b022d94fba95ec270cf6e7eae · fixed in 011ae80c49d9bfa5b4336f8bd387cd25c7593663; From 3b3009ea8abb713b022d94fba95ec270cf6e7eae · fixed in e1641177e7fb48a0a5a06658d4aab51da6656659; From 3b3009ea8abb713b022d94fba95ec270cf6e7eae · fixed in 3c330f1dee3cd92b57e19b9d21dc8ce5970b09be; From 3b3009ea8abb713b022d94fba95ec270cf6e7eae · fixed in 15564bd67e2975002f2a8e9defee33e321d3183f
- Linux Linux
6.4
- KernelLinux
From 6.4.0 · fixed in 6.6.120; From 6.7.0 · fixed in 6.12.64; From 6.13.0 · fixed in 6.18.3