syzbot

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BUG: KCSAN: data-race in batadv_bla_tx / batadv_bla_tx

write to 0xffff888134f81ca0 of 8 bytes by task 14443 on cpu 1:
 batadv_bla_update_own_backbone_gw net/batman-adv/bridge_loop_avoidance.c:576 [inline]
 batadv_bla_tx+0xe30/0x1300 net/batman-adv/bridge_loop_avoidance.c:2105
 batadv_interface_tx+0x293/0xc10 net/batman-adv/soft-interface.c:238
 __netdev_start_xmit include/linux/netdevice.h:4994 [inline]
 netdev_start_xmit include/linux/netdevice.h:5008 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3590
 dev_hard_start_xmit net/core/dev.c:3606 [inline]
 __dev_queue_xmit+0x869/0xf70 net/core/dev.c:4229
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4262
 __bpf_tx_skb net/core/filter.c:2114 [inline]
 __bpf_redirect_common net/core/filter.c:2153 [inline]
 __bpf_redirect+0x757/0x840 net/core/filter.c:2160
 ____bpf_clone_redirect net/core/filter.c:2429 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2401
 ___bpf_prog_run+0xc87/0x30c0 kernel/bpf/core.c:1558
 __bpf_prog_run512+0x70/0xa0 kernel/bpf/core.c:1786
 bpf_dispatcher_nop_func include/linux/bpf.h:727 [inline]
 __bpf_prog_run include/linux/filter.h:626 [inline]
 bpf_prog_run include/linux/filter.h:633 [inline]
 bpf_test_run+0x18b/0x400 net/bpf/test_run.c:120
 bpf_prog_test_run_skb+0x73d/0xed0 net/bpf/test_run.c:666
 bpf_prog_test_run kernel/bpf/syscall.c:3349 [inline]
 __sys_bpf+0x3ca4/0xa3c0 kernel/bpf/syscall.c:4651
 __do_sys_bpf kernel/bpf/syscall.c:4737 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4735 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4735
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffff888134f81ca0 of 8 bytes by task 14523 on cpu 0:
 batadv_bla_update_own_backbone_gw net/batman-adv/bridge_loop_avoidance.c:576 [inline]
 batadv_bla_tx+0xe30/0x1300 net/batman-adv/bridge_loop_avoidance.c:2105
 batadv_interface_tx+0x293/0xc10 net/batman-adv/soft-interface.c:238
 __netdev_start_xmit include/linux/netdevice.h:4994 [inline]
 netdev_start_xmit include/linux/netdevice.h:5008 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3590
 dev_hard_start_xmit net/core/dev.c:3606 [inline]
 __dev_queue_xmit+0x869/0xf70 net/core/dev.c:4229
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4262
 __bpf_tx_skb net/core/filter.c:2114 [inline]
 __bpf_redirect_common net/core/filter.c:2153 [inline]
 __bpf_redirect+0x757/0x840 net/core/filter.c:2160
 ____bpf_clone_redirect net/core/filter.c:2429 [inline]
 bpf_clone_redirect+0x168/0x1c0 net/core/filter.c:2401
 ___bpf_prog_run+0xc87/0x30c0 kernel/bpf/core.c:1558
 __bpf_prog_run512+0x70/0xa0 kernel/bpf/core.c:1786
 bpf_dispatcher_nop_func include/linux/bpf.h:727 [inline]
 __bpf_prog_run include/linux/filter.h:626 [inline]
 bpf_prog_run include/linux/filter.h:633 [inline]
 bpf_test_run+0x18b/0x400 net/bpf/test_run.c:120
 bpf_prog_test_run_skb+0x73d/0xed0 net/bpf/test_run.c:666
 bpf_prog_test_run kernel/bpf/syscall.c:3349 [inline]
 __sys_bpf+0x3ca4/0xa3c0 kernel/bpf/syscall.c:4651
 __do_sys_bpf kernel/bpf/syscall.c:4737 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4735 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4735
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000010002ce27 -> 0x000000010002ce28

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14523 Comm: syz-executor.2 Not tainted 5.16.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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