syzbot

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BUG: KCSAN: data-race in pfifo_fast_dequeue / pfifo_fast_enqueue

write to 0xffff88810e39b500 of 8 bytes by task 12516 on cpu 0:
 __ptr_ring_discard_one include/linux/ptr_ring.h:280 [inline]
 __ptr_ring_consume include/linux/ptr_ring.h:301 [inline]
 __skb_array_consume include/linux/skb_array.h:98 [inline]
 pfifo_fast_dequeue+0x25f/0x570 net/sched/sch_generic.c:651
 dequeue_skb+0x145/0xf20 net/sched/sch_generic.c:263
 qdisc_restart net/sched/sch_generic.c:366 [inline]
 __qdisc_run+0x72/0x180 net/sched/sch_generic.c:384
 qdisc_run include/net/pkt_sched.h:136 [inline]
 __dev_xmit_skb net/core/dev.c:3765 [inline]
 __dev_queue_xmit+0xa75/0x1570 net/core/dev.c:4119
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4184
 __bpf_tx_skb net/core/filter.c:2116 [inline]
 __bpf_redirect_common net/core/filter.c:2155 [inline]
 __bpf_redirect+0x67c/0x760 net/core/filter.c:2162
 ____bpf_clone_redirect net/core/filter.c:2448 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2420
 bpf_prog_79bab0a1566dd526+0x56/0x18c
 bpf_dispatcher_nop_func include/linux/bpf.h:651 [inline]
 bpf_test_run+0x278/0x460 net/bpf/test_run.c:50
 bpf_prog_test_run_skb+0x714/0xe90 net/bpf/test_run.c:582
 bpf_prog_test_run kernel/bpf/syscall.c:3122 [inline]
 __do_sys_bpf+0x3971/0x9950 kernel/bpf/syscall.c:4400
 __se_sys_bpf kernel/bpf/syscall.c:4340 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4340
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810e39b500 of 8 bytes by task 12512 on cpu 1:
 __ptr_ring_produce include/linux/ptr_ring.h:106 [inline]
 ptr_ring_produce include/linux/ptr_ring.h:129 [inline]
 skb_array_produce include/linux/skb_array.h:44 [inline]
 pfifo_fast_enqueue+0xdd/0x300 net/sched/sch_generic.c:626
 __dev_xmit_skb net/core/dev.c:3764 [inline]
 __dev_queue_xmit+0x785/0x1570 net/core/dev.c:4119
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4184
 __bpf_tx_skb net/core/filter.c:2116 [inline]
 __bpf_redirect_common net/core/filter.c:2155 [inline]
 __bpf_redirect+0x67c/0x760 net/core/filter.c:2162
 ____bpf_clone_redirect net/core/filter.c:2448 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2420
 bpf_prog_79bab0a1566dd526+0x56/0x390
 bpf_dispatcher_nop_func include/linux/bpf.h:651 [inline]
 bpf_test_run+0x278/0x460 net/bpf/test_run.c:50
 bpf_prog_test_run_skb+0x714/0xe90 net/bpf/test_run.c:582
 bpf_prog_test_run kernel/bpf/syscall.c:3122 [inline]
 __do_sys_bpf+0x3971/0x9950 kernel/bpf/syscall.c:4400
 __se_sys_bpf kernel/bpf/syscall.c:4340 [inline]
 __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4340
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12512 Comm: syz-executor.2 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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