In the Linux kernel, the following vulnerability has been resolved:

tipc: clear sock->sk on the failed-insert path in tipc_sk_create()

When tipc_sk_create() fails to insert the new socket (tipc_sk_insert()
returns non-zero), its error path frees the sk with sk_free() but leaves
sock->sk pointing at the freed object:

	if (tipc_sk_insert(tsk)) {
		sk_free(sk);
		pr_warn("Socket create failed; port number exhausted\n");
		return -EINVAL;
	}

This is harmless for plain socket(): the syscall layer clears sock->ops
before releasing, so tipc_release() is never called. It is not harmless
on the accept() path. tipc_accept() creates the pre-allocated child
socket with tipc_sk_create(net, new_sock, 0, kern); on failure it leaves
new_sock->sk dangling and new_sock->ops non-NULL, and do_accept() then
fput()s the new file, so __sock_release() -> tipc_release() runs
lock_sock(new_sock->sk) on the freed sk -- a use-after-free write of the
sk_lock spinlock.

tipc_release() already guards this exact "failed accept() releases a
pre-allocated child" case with "if (sk == NULL) return 0;", but the
guard is bypassed because tipc_sk_create() left sock->sk non-NULL
(dangling) rather than NULL.

Clear sock->sk on the failed-insert path so the existing tipc_release()
NULL check fires and the use-after-free is avoided.

The tipc_sk_insert() failure is reached when the per-netns socket
rhashtable hits its max_size (tsk_rht_params.max_size = 1048576, ~2M
elements) -- i.e. once a netns holds ~2M TIPC sockets every insert
returns -E2BIG.

  BUG: KASAN: slab-use-after-free in lock_sock_nested (net/core/sock.c:3839)
  Write of size 8 at addr ffff8880047cdc38 by task init/1
   lock_sock_nested (net/core/sock.c:3839)
   tipc_release (net/tipc/socket.c:638)
   __sock_release (net/socket.c:710)
   sock_close (net/socket.c:1501)
   __fput (fs/file_table.c:512)
  Allocated by task 1:
   sk_alloc (net/core/sock.c:2308)
   tipc_sk_create (net/tipc/socket.c:487)
   tipc_accept (net/tipc/socket.c:2744)
   do_accept (net/socket.c:2034)
  Freed by task 1:
   __sk_destruct (net/core/sock.c:2391)
   tipc_sk_create (net/tipc/socket.c:504)
   tipc_accept (net/tipc/socket.c:2744)
   do_accept (net/socket.c:2034)

https://git.kernel.org/stable/c/5f5a41a48dbf9eda57b67ce23e548602cf7195a6

https://git.kernel.org/stable/c/b07d87b31631edb6529e6cdcca790a7489d1250d

https://git.kernel.org/stable/c/ba0533fc163f905fe817cfabdf8ed4058da44800

https://git.kernel.org/stable/c/dd29891ed840f6b8d020b759d0dc4a00b1d6e4ea

https://git.kernel.org/stable/c/f9596b1566616a8be0592dbceccb6344a7c6f6bb

[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","programFiles":["net/tipc/socket.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"00aff3590fc0a73bddd3b743863c14e76fd35c0c","lessThan":"b07d87b31631edb6529e6cdcca790a7489d1250d","versionType":"git","status":"affected"},{"version":"00aff3590fc0a73bddd3b743863c14e76fd35c0c","lessThan":"dd29891ed840f6b8d020b759d0dc4a00b1d6e4ea","versionType":"git","status":"affected"},{"version":"00aff3590fc0a73bddd3b743863c14e76fd35c0c","lessThan":"5f5a41a48dbf9eda57b67ce23e548602cf7195a6","versionType":"git","status":"affected"},{"version":"00aff3590fc0a73bddd3b743863c14e76fd35c0c","lessThan":"f9596b1566616a8be0592dbceccb6344a7c6f6bb","versionType":"git","status":"affected"},{"version":"00aff3590fc0a73bddd3b743863c14e76fd35c0c","lessThan":"ba0533fc163f905fe817cfabdf8ed4058da44800","versionType":"git","status":"affected"},{"version":"638fa20b618b2bbcf86da71231624cc82121a036","versionType":"git","status":"affected"},{"version":"7bc9e7f70bc57d8f02ffea2a42094281effb15ef","versionType":"git","status":"affected"},{"version":"ef488669b2652bde5b6ee5a409a5b048a2a50db4","versionType":"git","status":"affected"},{"version":"4919d82f7041157a421ca9bf39a78551d5ad8a1b","versionType":"git","status":"affected"},{"version":"efa78f2ae363428525fb4981bb63c555ee79f3c7","versionType":"git","status":"affected"},{"version":"833ecd0eae76eadf81d6d747bb5bc992d1151867","versionType":"git","status":"affected"},{"version":"3b2957fc09fe1ac7f07f40dd50dd5f93e3f3a7a2","versionType":"git","status":"affected"},{"version":"4.9.324","lessThan":"4.10","versionType":"semver","status":"affected"},{"version":"4.14.289","lessThan":"4.15","versionType":"semver","status":"affected"},{"version":"4.19.253","lessThan":"4.20","versionType":"semver","status":"affected"},{"version":"5.4.207","lessThan":"5.5","versionType":"semver","status":"affected"},{"version":"5.10.132","lessThan":"5.11","versionType":"semver","status":"affected"},{"version":"5.15.56","lessThan":"5.16","versionType":"semver","status":"affected"},{"version":"5.18.13","lessThan":"5.19","versionType":"semver","status":"affected"}]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","programFiles":["net/tipc/socket.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"5.19","status":"affected"},{"version":"0","lessThan":"5.19","versionType":"semver","status":"unaffected"},{"version":"6.6.148","lessThanOrEqual":"6.6.*","versionType":"semver","status":"unaffected"},{"version":"6.12.101","lessThanOrEqual":"6.12.*","versionType":"semver","status":"unaffected"},{"version":"6.18.42","lessThanOrEqual":"6.18.*","versionType":"semver","status":"unaffected"},{"version":"7.1.6","lessThanOrEqual":"7.1.*","versionType":"semver","status":"unaffected"},{"version":"7.2-rc5","lessThanOrEqual":"*","versionType":"original_commit_for_fix","status":"unaffected"}]}]