| TITLE: INFO: suspicious RCU usage in ipv6_flowlabel_opt |
| |
| [ 37.911413] =============================== |
| [ 37.912153] [ INFO: suspicious RCU usage. ] |
| [ 37.912790] 4.1.15+ #4 Not tainted |
| [ 37.913339] ------------------------------- |
| [ 37.914040] /linux/net/ipv6/ip6_flowlabel.c:543 suspicious rcu_dereference_check() usage! |
| [ 37.915642] |
| [ 37.915642] other info that might help us debug this: |
| [ 37.915642] |
| [ 37.916873] |
| [ 37.916873] rcu_scheduler_active = 1, debug_locks = 0 |
| [ 37.917866] 2 locks held by syz-executor3/9912: |
| [ 37.918512] #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff817c1ca2>] do_ipv6_setsockopt.isra.13+0xc2/0x1340 |
| [ 37.920066] #1: (ip6_sk_fl_lock){+.....}, at: [<ffffffff817dfb27>] ipv6_flowlabel_opt+0x437/0xe00 |
| [ 37.921525] |
| [ 37.921525] stack backtrace: |
| [ 37.922226] CPU: 1 PID: 9912 Comm: syz-executor3 Not tainted 4.1.15+ #4 |
| [ 37.923181] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 |
| [ 37.924340] 0000000000000001 ffff880071227c28 ffffffff818c5ac5 ffff88007afd4c40 |
| [ 37.925520] ffff880071227c58 ffffffff818b777b 0000000000000000 ffff88007af73cd0 |
| [ 37.926688] ffff88007af73c68 ffffffff81c46220 ffff880071227ce0 ffffffff817dfb87 |
| [ 37.927769] Call Trace: |
| [ 37.928122] [<ffffffff818c5ac5>] dump_stack+0x4b/0x63 |
| [ 37.928832] [<ffffffff818b777b>] lockdep_rcu_suspicious.cold.44+0xc4/0xe4 |
| [ 37.929865] [<ffffffff817dfb87>] ipv6_flowlabel_opt+0x497/0xe00 |
| [ 37.930900] [<ffffffff810996ad>] ? trace_hardirqs_on_caller+0xfd/0x1e0 |
| [ 37.932119] [<ffffffff816a31b1>] ? lock_sock_nested+0x41/0xb0 |
| [ 37.933059] [<ffffffff8109979d>] ? trace_hardirqs_on+0xd/0x10 |
| [ 37.933873] [<ffffffff817c25df>] do_ipv6_setsockopt.isra.13+0x9ff/0x1340 |
| [ 37.934837] [<ffffffff8107fd6a>] ? try_to_wake_up+0x21a/0x390 |
| [ 37.935634] [<ffffffff81316941>] ? plist_check_head+0x21/0x30 |
| [ 37.936428] [<ffffffff81099fb5>] ? __lock_acquire+0x535/0x1ab0 |
| [ 37.937238] [<ffffffff81097dd1>] ? __lock_is_held+0x51/0x80 |
| [ 37.938032] [<ffffffff817c2f73>] ipv6_setsockopt+0x53/0xc0 |
| [ 37.938783] [<ffffffff8172e7ab>] tcp_setsockopt+0x1b/0x30 |
| [ 37.939530] [<ffffffff816a289f>] sock_common_setsockopt+0xf/0x20 |
| [ 37.940355] [<ffffffff816a15bc>] SyS_setsockopt+0x6c/0xd0 |
| [ 37.941114] [<ffffffff818e2dae>] system_call_fastpath+0x12/0x76 |
