FYI, we noticed the following commit (built with gcc-7): commit: 327fecdaf39ab7163e6d189e19abdadf4555b002 ("[PATCH] sctp: set ooo_okay properly for Transmit Packet Steering") url: https://github.com/0day-ci/linux/commits/Wally-Zhao/sctp-set-ooo_okay-properly-for-Transmit-Packet-Steering/20191101-171354 in testcase: boot on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +-------------------------------------------------------+------------+------------+ | | 52340b82cf | 327fecdaf3 | +-------------------------------------------------------+------------+------------+ | boot_successes | 32 | 48 | | boot_failures | 3 | 28 | | BUG:kernel_hang_in_test_stage | 3 | 14 | | BUG:kernel_NULL_pointer_dereference,address | 0 | 14 | | Oops:#[##] | 0 | 14 | | RIP:sctp_packet_transmit | 0 | 14 | | Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 0 | 13 | +-------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 35.312661] BUG: kernel NULL pointer dereference, address: 00000000000005d8 [ 35.316225] #PF: supervisor read access in kernel mode [ 35.319178] #PF: error_code(0x0000) - not-present page [ 35.322078] PGD 800000021b569067 P4D 800000021b569067 PUD 21b688067 PMD 0 [ 35.325629] Oops: 0000 [#1] SMP PTI [ 35.327965] CPU: 0 PID: 3148 Comm: trinity-c5 Not tainted 5.4.0-rc3-01107-g327fecdaf39ab #12 [ 35.332863] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 35.337932] RIP: 0010:sctp_packet_transmit+0x767/0x822 [ 35.340818] Code: 8a 45 40 d0 e8 83 e0 08 88 c2 8a 43 78 83 e0 f7 09 d0 88 43 78 41 f6 45 24 08 74 04 80 4b 7a 20 48 8b 04 24 4c 89 ee 48 89 df <83> b8 d8 05 00 00 00 0f 94 c0 c1 e0 07 88 c2 8a 43 78 83 e0 7f 09 [ 35.350270] RSP: 0000:ffffc90000003ac0 EFLAGS: 00010246 [ 35.353243] RAX: 0000000000000000 RBX: ffff888219803e00 RCX: 0000000000000007 [ 35.356838] RDX: 0000000000000000 RSI: ffff888218842800 RDI: ffff888219803e00 [ 35.360408] RBP: ffff888218842a10 R08: 00000000000002c0 R09: ffffffff81bb406d [ 35.364054] R10: 0000000000000034 R11: 000000007f000001 R12: ffff888219802700 [ 35.367715] R13: ffff888218842800 R14: 0000000000000000 R15: ffff888219803e00 [ 35.371276] FS: 0000000000000000(0000) GS:ffff88823fc00000(0063) knlGS:000000000a47b880 [ 35.376104] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 35.379260] CR2: 00000000000005d8 CR3: 0000000218ee2000 CR4: 00000000000406f0 [ 35.382827] DR0: fffffffff7277000 DR1: 0000000000000000 DR2: 0000000000000000 [ 35.386346] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 [ 35.389854] Call Trace: [ 35.391837] [ 35.393688] ? sctp_sf_do_5_1B_init+0x153/0x2b1 [ 35.396438] sctp_do_sm+0xa52/0x149b [ 35.398853] ? tcp_rcv_established+0x345/0x396 [ 35.401502] ? tcp_v4_do_rcv+0x9b/0x167 [ 35.403981] ? tcp_v4_rcv+0x54a/0x778 [ 35.406396] ? raw_local_deliver+0x1dc/0x22c [ 35.409022] ? raw_local_deliver+0x1f1/0x22c [ 35.411594] ? update_group_capacity+0x23/0x193 [ 35.414340] ? cpumask_next_and+0x19/0x1a [ 35.416826] ? update_sd_lb_stats+0x4ae/0x4d2 [ 35.419471] sctp_endpoint_bh_rcv+0x19d/0x1e1 [ 35.422148] sctp_rcv+0x98b/0xa9b [ 35.424311] ? sock_def_readable+0x4d/0x57 [ 35.426726] ? __sock_queue_rcv_skb+0x1ad/0x1bc [ 35.429382] ? ip_protocol_deliver_rcu+0x76/0xeb [ 35.432068] ? __sctp_lookup_association+0x24/0x24 [ 35.434839] ip_protocol_deliver_rcu+0x76/0xeb [ 35.437474] ip_local_deliver+0x8a/0x96 [ 35.439960] __netif_receive_skb_one_core+0x71/0x93 [ 35.442693] process_backlog+0x86/0x125 [ 35.445115] net_rx_action+0x11e/0x2b9 [ 35.447605] __do_softirq+0x151/0x2dd [ 35.450085] do_softirq_own_stack+0x2a/0x40 [ 35.452746] [ 35.454643] do_softirq+0x3f/0x56 [ 35.456910] __local_bh_enable_ip+0x49/0x58 [ 35.459619] ip_finish_output2+0x30a/0x36c [ 35.462217] ? ip_skb_dst_mtu+0x53/0x83 [ 35.464616] ? __ip_queue_xmit+0x2a8/0x2e0 [ 35.467261] __ip_queue_xmit+0x2a8/0x2e0 [ 35.469775] ? slab_free_freelist_hook+0x19/0x68 [ 35.472823] sctp_packet_transmit+0x790/0x822 [ 35.475401] ? sctp_packet_config+0x10c/0x1fa [ 35.478101] sctp_outq_flush_ctrl+0x124/0x20f [ 35.481001] sctp_outq_flush+0x66/0x647 [ 35.483502] sctp_do_sm+0x1309/0x149b [ 35.485818] ? trace_hardirqs_on+0x2e/0x3a [ 35.488309] ? ___slab_alloc+0xcb/0x3fe [ 35.490698] ? sctp_stream_init_ext+0x2c/0x8a [ 35.493147] ? sctp_ulpq_tail_event+0x191/0x1a8 [ 35.495543] ? tracer_hardirqs_on+0x1b/0xf6 [ 35.497999] sctp_primitive_ASSOCIATE+0x33/0x36 [ 35.500526] sctp_sendmsg_to_asoc+0x2f2/0x48a [ 35.502810] ? sctp_connect_new_asoc+0xe1/0x176 [ 35.505001] sctp_sendmsg+0x717/0x795 [ 35.507337] ? memblock_search_pfn_nid+0x4b/0x5f [ 35.509960] ? sock_sendmsg_nosec+0x2b/0x3c [ 35.512459] sock_sendmsg_nosec+0x2b/0x3c [ 35.514721] ___sys_sendmsg+0x1a8/0x22f [ 35.516894] ? ___might_sleep+0x3b/0x144 [ 35.519058] ? ___might_sleep+0x3b/0x144 [ 35.520991] ? timerqueue_add+0x5e/0x62 [ 35.522512] ? enqueue_hrtimer+0x90/0x9a [ 35.524303] ? _raw_spin_unlock_irqrestore+0x19/0x2b [ 35.526195] ? hrtimer_start_range_ns+0x1eb/0x20f [ 35.527856] ? tracer_hardirqs_on+0x1b/0xf6 [ 35.529383] ? __sys_sendmsg+0x5e/0x91 [ 35.531387] __sys_sendmsg+0x5e/0x91 [ 35.533398] do_int80_syscall_32+0x58/0x65 [ 35.535156] entry_INT80_compat+0x87/0xa0 [ 35.537606] Modules linked in: [ 35.539765] CR2: 00000000000005d8 [ 35.541952] ---[ end trace 1e09b73b4a0b8b3e ]--- To reproduce: # build kernel cd linux cp config-5.4.0-rc3-01107-g327fecdaf39ab .config make HOSTCC=gcc-7 CC=gcc-7 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Rong Chen