Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: net/handshake: hand off the pinned file reference to accept_doit handshake_req_next() removes the request from the per-net pending list and drops hn_lock before handshake_nl_accept_doit() reads req->hr_sk->sk_socket and dereferences sock->file (once in FD_PREPARE() and again in get_file()). In that window a consumer running tls_handshake_cancel() followed by sockfd_put() (svc_sock_free) or __fput_sync() (xs_reset_transport) releases sock->file. sock_release() then runs sock_orphan(), zeroing sk_socket, and frees the struct socket. The accept-side code either reads NULL through sk_socket or chases freed memory. The submit-side sock_hold() does not prevent this. sk_refcnt protects struct sock, but struct socket and sock->file are independently refcounted via the file descriptor the consumer owns. Pinning sk leaves sock and sock->file unprotected. Retarget the accept-side dereferences at req->hr_file, which was pinned at submit time, instead of req->hr_sk->sk_socket->file. Pinning on its own is not sufficient: a consumer that cancels between handshake_req_next() returning and accept_doit reaching FD_PREPARE() takes the !remove_pending() branch in handshake_req_cancel() and drops hr_file before the accept side takes its own reference. Hand off an additional file reference inside handshake_req_next(), under hn_lock, so the accept side operates on a reference that no concurrent handshake_req_cancel() can revoke. FD_PREPARE() consumes that handed-off reference, either by transferring it to the new fd in fd_publish() or by dropping it in the cleanup destructor on error; the explicit get_file() that previously balanced FD_PREPARE() is therefore redundant and goes away. Update handshake_req_cancel_test2 and _test3 to simulate the FD_PREPARE() consumption with an fput() so the kunit file-count assertions stay balanced.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 3b3009ea8abb713b022d94fba95ec270cf6e7eae before b869e3e4ce1996df23b3efdbbe9a64c4ab81d745; affected 3b3009ea8abb713b022d94fba95ec270cf6e7eae before 2f28dbb30b88eafab8d49aaec94710b4e12dea8e; affected 3b3009ea8abb713b022d94fba95ec270cf6e7eae before 68eba6519cbd6359fb554a9720f3a3b6b2eba23f; affected 3b3009ea8abb713b022d94fba95ec270cf6e7eae before c06876d4fac38f35820946ee3b1be7d7da799cd4; affected 3b3009ea8abb713b022d94fba95ec270cf6e7eae before f4251190e58b209999c1ba9e6d2976136a1be055 |
| Linux / Linux | affected 6.4; unaffected 0 before 6.4; unaffected 6.6.160 through 6.6.*; unaffected 6.12.114 through 6.12.*; unaffected 6.18.44 through 6.18.*; unaffected 7.0.12 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/b869e3e4ce1996df23b3efdbbe9a64c4ab81d745
- https://git.kernel.org/stable/c/2f28dbb30b88eafab8d49aaec94710b4e12dea8e
- https://git.kernel.org/stable/c/68eba6519cbd6359fb554a9720f3a3b6b2eba23f
- https://git.kernel.org/stable/c/c06876d4fac38f35820946ee3b1be7d7da799cd4
- https://git.kernel.org/stable/c/f4251190e58b209999c1ba9e6d2976136a1be055
ADP enrichment
No English description supplied.
No references supplied.