==================================================================
BUG: KCSAN: data-race in batadv_tt_local_add / batadv_tt_local_add

read to 0xffff8880a3070798 of 2 bytes by task 18930 on cpu 0:
 batadv_tt_local_add+0x11b/0x1020 net/batman-adv/translation-table.c:672
 batadv_interface_tx+0x398/0xae0 net/batman-adv/soft-interface.c:249
 __netdev_start_xmit include/linux/netdevice.h:4413 [inline]
 netdev_start_xmit include/linux/netdevice.h:4427 [inline]
 xmit_one net/core/dev.c:3199 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3215
 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792
 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825
 __bpf_tx_skb net/core/filter.c:2060 [inline]
 __bpf_redirect_common net/core/filter.c:2099 [inline]
 __bpf_redirect+0x4b4/0x710 net/core/filter.c:2106
 ____bpf_clone_redirect net/core/filter.c:2139 [inline]
 bpf_clone_redirect+0x1a5/0x1f0 net/core/filter.c:2111
 bpf_prog_bb15b996d00816f9+0x4b6/0x1000
 bpf_test_run+0x1c3/0x490 net/bpf/test_run.c:44
 bpf_prog_test_run_skb+0x4da/0x840 net/bpf/test_run.c:310
 bpf_prog_test_run kernel/bpf/syscall.c:2120 [inline]
 __do_sys_bpf+0x1664/0x2b90 kernel/bpf/syscall.c:2896
 __se_sys_bpf kernel/bpf/syscall.c:2837 [inline]
 __x64_sys_bpf+0x4c/0x60 kernel/bpf/syscall.c:2837
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880a3070798 of 2 bytes by task 18935 on cpu 1:
 batadv_tt_local_add+0x298/0x1020 net/batman-adv/translation-table.c:820
 batadv_interface_tx+0x398/0xae0 net/batman-adv/soft-interface.c:249
 __netdev_start_xmit include/linux/netdevice.h:4413 [inline]
 netdev_start_xmit include/linux/netdevice.h:4427 [inline]
 xmit_one net/core/dev.c:3199 [inline]
 dev_hard_start_xmit+0xef/0x430 net/core/dev.c:3215
 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792
 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825
 __bpf_tx_skb net/core/filter.c:2060 [inline]
 __bpf_redirect_common net/core/filter.c:2099 [inline]
 __bpf_redirect+0x4b4/0x710 net/core/filter.c:2106
 ____bpf_clone_redirect net/core/filter.c:2139 [inline]
 bpf_clone_redirect+0x1a5/0x1f0 net/core/filter.c:2111
 bpf_prog_bb15b996d00816f9+0xd0c/0x1000
 bpf_test_run+0x1c3/0x490 net/bpf/test_run.c:44
 bpf_prog_test_run_skb+0x4da/0x840 net/bpf/test_run.c:310
 bpf_prog_test_run kernel/bpf/syscall.c:2120 [inline]
 __do_sys_bpf+0x1664/0x2b90 kernel/bpf/syscall.c:2896
 __se_sys_bpf kernel/bpf/syscall.c:2837 [inline]
 __x64_sys_bpf+0x4c/0x60 kernel/bpf/syscall.c:2837
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18935 Comm: syz-executor.0 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================