6.6-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 5b0af621c3f6ef9261cf6067812f2fd9943acb4b ]
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>
Fixes: 8c7138b33e5c ("net: Unpublish sk from sk_reuseport_cb before call_rcu") Reported-by: syzbot+b3e02953598f447d4d2a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6772f2f4.050a0220.2f3838.04cb.GAE@google.com/... Signed-off-by: Eric Dumazet edumazet@google.com Cc: Martin KaFai Lau kafai@fb.com Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Link: https://patch.msgid.link/20241231160527.3994168-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/sock.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/core/sock.c b/net/core/sock.c index bc2a4e38dcea..84ba3f67bca9 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1133,7 +1133,10 @@ int sk_setsockopt(struct sock *sk, int level, int optname, sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE); break; case SO_REUSEPORT: - sk->sk_reuseport = valbool; + if (valbool && !sk_is_inet(sk)) + ret = -EOPNOTSUPP; + else + sk->sk_reuseport = valbool; break; case SO_TYPE: case SO_PROTOCOL: