On Sat, 2015-12-05 at 19:25 -0500, Dave Jones wrote: > =============================== > [ INFO: suspicious RCU usage. ] > 4.4.0-rc3-think+ #8 Tainted: G W > ------------------------------- > net/sctp/ipv6.c:331 suspicious rcu_dereference_check() usage! > > other info that might help us debug this: > > > rcu_scheduler_active = 1, debug_locks = 0 > 1 lock held by trinity-c2/15441: > #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffffc065fc01>] > sctp_sendmsg+0x501/0x16a0 [sctp] > > stack backtrace: > CPU: 2 PID: 15441 Comm: trinity-c2 Tainted: G W 4.4.0-rc3-think+ > #8 > ffffffffffffff9b ffff880458d677c8 ffffffffab530f11 ffff88045f1db700 > ffff880458d677f8 ffffffffab12d248 ffff880452b13f80 ffff880452b13f60 > 0000000000000000 ffff88045ad45280 ffff880458d67970 ffffffffc0673a7c > Call Trace: > [<ffffffffab530f11>] dump_stack+0x4e/0x7d > [<ffffffffab12d248>] lockdep_rcu_suspicious+0xf8/0x110 > [<ffffffffc0673a7c>] sctp_v6_get_dst+0xacc/0xb30 [sctp] > [<ffffffffc0673666>] ? sctp_v6_get_dst+0x6b6/0xb30 [sctp] > [<ffffffffc0672fb0>] ? sctp_inet6_send_verify+0x180/0x180 [sctp] > [<ffffffffab6b1c69>] ? get_random_bytes+0x69/0x150 > [<ffffffffab6b0950>] ? extract_buf+0x370/0x370 > [<ffffffffab12afa2>] ? __lock_is_held+0x92/0xd0 > [<ffffffffc0647390>] ? sctp_transport_new+0x2f0/0x320 [sctp] > [<ffffffffc0647786>] sctp_transport_route+0x66/0x1c0 [sctp] > [<ffffffffc0644d02>] sctp_assoc_add_peer+0x242/0x680 [sctp] > [<ffffffffc06603d1>] sctp_sendmsg+0xcd1/0x16a0 [sctp] > [<ffffffffab12f64f>] ? mark_lock+0x6f/0x8a0 > [<ffffffffc065f700>] ? sctp_id2assoc+0x140/0x140 [sctp] > [<ffffffffab130620>] ? debug_check_no_locks_freed+0x1b0/0x1b0 > [<ffffffffab12f64f>] ? mark_lock+0x6f/0x8a0 > [<ffffffffab015269>] ? native_sched_clock+0x69/0x160 > [<ffffffffab5606e7>] ? debug_smp_processor_id+0x17/0x20 > [<ffffffffab0eb1e1>] ? preempt_count_sub+0xc1/0x120 > [<ffffffffabbb3d0e>] inet_sendmsg+0x18e/0x270 > [<ffffffffabbb3b85>] ? inet_sendmsg+0x5/0x270 > [<ffffffffabaa4ee8>] SYSC_sendto+0x1d8/0x2c0 > [<ffffffffabaa4d10>] ? sock_create_kern+0x20/0x20 > [<ffffffffab12af35>] ? __lock_is_held+0x25/0xd0 > [<ffffffffab1300c6>] ? trace_hardirqs_on_caller+0x186/0x280 > [<ffffffffab1301cd>] ? trace_hardirqs_on+0xd/0x10 > [<ffffffffab253a5d>] ? context_tracking_exit+0x1d/0x20 > [<ffffffffab002fdf>] ? enter_from_user_mode+0x1f/0x50 > [<ffffffffab0031b2>] ? syscall_trace_enter_phase1+0x1a2/0x240 > [<ffffffffab003010>] ? enter_from_user_mode+0x50/0x50 > [<ffffffffabcb735a>] ? int_ret_from_sys_call+0x52/0x9f > [<ffffffffab1300c6>] ? trace_hardirqs_on_caller+0x186/0x280 > [<ffffffffab002017>] ? trace_hardirqs_on_thunk+0x17/0x19 > [<ffffffffabaa5aee>] SyS_sendto+0xe/0x10 > [<ffffffffabcb71d7>] entry_SYSCALL_64_fastpath+0x12/0x6b > > This maybe ? > > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c > index acb45b8c2a9d..7081183f4d9f 100644 > --- a/net/sctp/ipv6.c > +++ b/net/sctp/ipv6.c > @@ -328,7 +328,9 @@ static void sctp_v6_get_dst(struct sctp_transport *t, > union sctp_addr *saddr, > if (baddr) { > fl6->saddr = baddr->v6.sin6_addr; > fl6->fl6_sport = baddr->v6.sin6_port; > + rcu_read_lock(); > final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); > + rcu_read_unlock(); > dst = ip6_dst_lookup_flow(sk, fl6, final_p); > } >
Hmm, better use : diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index acb45b8c2a9d..d28c0b4c9128 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -323,14 +323,13 @@ static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, } } } - rcu_read_unlock(); - if (baddr) { fl6->saddr = baddr->v6.sin6_addr; fl6->fl6_sport = baddr->v6.sin6_port; final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); dst = ip6_dst_lookup_flow(sk, fl6, final_p); } + rcu_read_unlock(); out: if (!IS_ERR_OR_NULL(dst)) { -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html