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

net: restrict SO_REUSEPORT to inet sockets

After blamed commit, crypto sockets could accidentally be destroyed
from RCU call back, as spotted by zyzbot [1].

Trying to acquire a mutex in RCU callback is not allowed.

Restrict SO_REUSEPORT socket option to inet sockets.

v1 of this patch supported TCP, UDP and SCTP sockets,
but fcnal-test.sh test needed RAW and ICMP support.

[1]
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:562
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 24, name: ksoftirqd/1
preempt_count: 100, expected: 0
RCU nest depth: 0, expected: 0
1 lock held by ksoftirqd/1/24:
  #0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
  #0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2561 [inline]
  #0: ffffffff8e937ba0 (rcu_callback){....}-{0:0}, at: rcu_core+0xa37/0x17a0 kernel/rcu/tree.c:2823
Preemption disabled at:
 [<ffffffff8161c8c8>] softirq_handle_begin kernel/softirq.c:402 [inline]
 [<ffffffff8161c8c8>] handle_softirqs+0x128/0x9b0 kernel/softirq.c:537
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.13.0-rc3-syzkaller-00174-ga024e377efed #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:94 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
  __might_resched+0x5d4/0x780 kernel/sched/core.c:8758
  __mutex_lock_common kernel/locking/mutex.c:562 [inline]
  __mutex_lock+0x131/0xee0 kernel/locking/mutex.c:735
  crypto_put_default_null_skcipher+0x18/0x70 crypto/crypto_null.c:179
  aead_release+0x3d/0x50 crypto/algif_aead.c:489
  alg_do_release crypto/af_alg.c:118 [inline]
  alg_sock_destruct+0x86/0xc0 crypto/af_alg.c:502
  __sk_destruct+0x58/0x5f0 net/core/sock.c:2260
  rcu_do_batch kernel/rcu/tree.c:2567 [inline]
  rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
  handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
  run_ksoftirqd+0xca/0x130 kernel/softirq.c:950
  smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
  kthread+0x2f0/0x390 kernel/kthread.c:389
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

https://git.kernel.org/stable/c/3257813a3ae7462ac5cde04e120806f0c0776850

https://git.kernel.org/stable/c/579cfa595af1e00ccc9c3a849a4add6bba8b4bad

https://git.kernel.org/stable/c/5b0af621c3f6ef9261cf6067812f2fd9943acb4b

https://git.kernel.org/stable/c/ad2ad4cd11af9d63187cd074314b71b7cf8a2a59

https://git.kernel.org/stable/c/ad91a2dacbf8c26a446658cdd55e8324dfeff1e7