syzbot

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BUG: KMSAN: uninit-value in unwind_next_frame+0x4cc/0xf30 arch/x86/kernel/unwind_frame.c:287
CPU: 0 PID: 22178 Comm: vhost-22177 Not tainted 4.20.0-rc7+ #12
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:611
 __msan_warning+0x81/0xf0 mm/kmsan/kmsan_instr.c:295
 unwind_next_frame+0x4cc/0xf30 arch/x86/kernel/unwind_frame.c:287
 __save_stack_trace+0x78b/0xb90 arch/x86/kernel/stacktrace.c:44
 save_stack_trace+0xa2/0xe0 arch/x86/kernel/stacktrace.c:60
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:202 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:217 [inline]
 kmsan_internal_chain_origin+0x134/0x230 mm/kmsan/kmsan.c:437
 __msan_chain_origin+0x74/0xe0 mm/kmsan/kmsan_instr.c:182
 __skb_clone+0x889/0x990 net/core/skbuff.c:866
 skb_clone+0x3e8/0x580 net/core/skbuff.c:1287
 skb_share_check include/linux/skbuff.h:1568 [inline]
 packet_rcv_spkt+0x25b/0x960 net/packet/af_packet.c:1817
 deliver_skb net/core/dev.c:1945 [inline]
 deliver_ptype_list_skb net/core/dev.c:1960 [inline]
 __netif_receive_skb_core+0x36c4/0x52c0 net/core/dev.c:4904
 __netif_receive_skb_one_core net/core/dev.c:4944 [inline]
 __netif_receive_skb net/core/dev.c:5056 [inline]
 netif_receive_skb_internal+0x4d8/0x9a0 net/core/dev.c:5159
 napi_skb_finish net/core/dev.c:5616 [inline]
 napi_gro_receive+0x664/0xad0 net/core/dev.c:5647
 receive_buf+0x598a/0x8230 drivers/net/virtio_net.c:1041
 virtnet_receive drivers/net/virtio_net.c:1303 [inline]
 virtnet_poll+0xddf/0x1c60 drivers/net/virtio_net.c:1390
 napi_poll net/core/dev.c:6287 [inline]
 net_rx_action+0x816/0x1aa0 net/core/dev.c:6353
 __do_softirq+0x53f/0x93a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x214/0x250 kernel/softirq.c:416
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 do_IRQ+0x2bb/0x3b0 arch/x86/kernel/irq.c:258
 common_interrupt+0x2e/0x2e arch/x86/entry/entry_64.S:588
 </IRQ>
RIP: 0010:_raw_spin_unlock_irqrestore+0x4b/0x70 kernel/locking/spinlock.c:185
Code: 00 8b b8 88 0c 00 00 48 8b 00 48 85 c0 75 28 48 89 df e8 98 6c 4a f7 c6 00 00 c6 03 00 4d 85 e4 75 1c 4c 89 7d d8 ff 75 d8 9d <48> 83 c4 08 5b 41 5c 41 5e 41 5f 5d c3 e8 83 76 4a f7 eb d1 44 89
RSP: 0018:ffff888047edfe30 EFLAGS: 00000286 ORIG_RAX: ffffffffffffffd7
RAX: ffff888047ebf8a8 RBX: ffff888047eaf8a8 RCX: ffff888047ebf8a8
RDX: ffff888047ecf8a8 RSI: 0000160000000000 RDI: ccccccccccccd000
RBP: ffff888047edfe58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff8169e0b0 R12: 0000000000000000
R13: ffff888047eaf8a0 R14: 0000000000000000 R15: 0000000000000286
 spin_unlock_irqrestore include/linux/spinlock.h:384 [inline]
 complete+0x10e/0x170 kernel/sched/completion.c:37
 kthread+0x3c6/0x4e0 kernel/kthread.c:240
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Local variable description: ----sackh.i.i@sctp_do_sm
Variable was created at:
 sctp_do_sm+0x109/0x9b20 net/sctp/sm_sideeffect.c:1169
 sctp_cmd_process_sack net/sctp/sm_sideeffect.c:814 [inline]
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1389 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1220 [inline]
 sctp_do_sm+0x43b9/0x9b20 net/sctp/sm_sideeffect.c:1191
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