==================================================================
BUG: KASAN: use-after-free in is_multicast_ether_addr_64bits include/linux/etherdevice.h:136 [inline]
BUG: KASAN: use-after-free in netif_receive_generic_xdp net/core/dev.c:4294 [inline]
BUG: KASAN: use-after-free in do_xdp_generic+0x612/0x1500 net/core/dev.c:4392
Read of size 8 at addr ffff88809ec0cfff by task syz-executor.1/10881

CPU: 1 PID: 10881 Comm: syz-executor.1 Tainted: G        W         5.4.19-syzkaller-00493-gf7d5a6d230b5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b0/0x228 lib/dump_stack.c:118
 print_address_description+0x96/0x5d0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 is_multicast_ether_addr_64bits include/linux/etherdevice.h:136 [inline]
 netif_receive_generic_xdp net/core/dev.c:4294 [inline]
 do_xdp_generic+0x612/0x1500 net/core/dev.c:4392
 tun_get_user+0x2498/0x3d10 drivers/net/tun.c:1935
 tun_chr_write_iter+0x134/0x1c0 drivers/net/tun.c:2026
 do_iter_readv_writev+0x5fa/0x890 include/linux/fs.h:1909
 do_iter_write+0x180/0x590 fs/read_write.c:973
 vfs_writev fs/read_write.c:1018 [inline]
 do_writev+0x2cd/0x560 fs/read_write.c:1061
 __do_sys_writev fs/read_write.c:1134 [inline]
 __se_sys_writev fs/read_write.c:1131 [inline]
 __x64_sys_writev+0x7d/0x90 fs/read_write.c:1131
 do_syscall_64+0xc0/0x100 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c581
Code: 75 14 b8 14 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 e4 b7 fb ff c3 48 83 ec 08 e8 fa 2c 00 00 48 89 04 24 b8 14 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 43 2d 00 00 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f64036aaba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00000000000000e2 RCX: 000000000045c581
RDX: 0000000000000001 RSI: 00007f64036aac00 RDI: 00000000000000f0
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000b7c R14: 00000000004cd906 R15: 000000000076bf2c

The buggy address belongs to the page:
page:ffffea00027b0300 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
raw: 4000000000000000 ffffea00027b0308 ffffea00027b0308 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809ec0ce80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88809ec0cf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88809ec0cf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                                ^
 ffff88809ec0d000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88809ec0d080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
------------[ cut here ]------------
Illegal XDP return value 4294967274, expect packet loss!
WARNING: CPU: 1 PID: 10881 at net/core/filter.c:6907 bpf_warn_invalid_xdp_action+0x5a/0x60 net/core/filter.c:6905
Modules linked in:
CPU: 1 PID: 10881 Comm: syz-executor.1 Tainted: G    B   W         5.4.19-syzkaller-00493-gf7d5a6d230b5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:bpf_warn_invalid_xdp_action+0x5a/0x60 net/core/filter.c:6905
Code: e8 db 7b 5e fe 83 fb 04 48 c7 c0 6b 71 56 84 48 c7 c6 73 71 56 84 48 0f 47 f0 48 c7 c7 3e 71 56 84 89 da 31 c0 e8 76 51 35 fe <0f> 0b eb bc 66 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 50 4c 89
RSP: 0018:ffff888194687668 EFLAGS: 00010246
RAX: 6adf886efa3c9100 RBX: 00000000ffffffea RCX: 0000000000040000
RDX: ffffc90006da2000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffff888194687670 R08: ffffffff812d0560 R09: 0000000000000003
R10: ffffed10328d0e39 R11: 0000000000000004 R12: dffffc0000000000
R13: 00000000ffffffea R14: dffffc0000000000 R15: ffff888195bbe140
FS:  00007f64036ab700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d7e18 CR3: 00000001d8deb002 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 netif_receive_generic_xdp net/core/dev.c:4343 [inline]
 do_xdp_generic+0xd2d/0x1500 net/core/dev.c:4392
 tun_get_user+0x2498/0x3d10 drivers/net/tun.c:1935
 tun_chr_write_iter+0x134/0x1c0 drivers/net/tun.c:2026
 do_iter_readv_writev+0x5fa/0x890 include/linux/fs.h:1909
 do_iter_write+0x180/0x590 fs/read_write.c:973
 vfs_writev fs/read_write.c:1018 [inline]
 do_writev+0x2cd/0x560 fs/read_write.c:1061
 __do_sys_writev fs/read_write.c:1134 [inline]
 __se_sys_writev fs/read_write.c:1131 [inline]
 __x64_sys_writev+0x7d/0x90 fs/read_write.c:1131
 do_syscall_64+0xc0/0x100 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c581
Code: 75 14 b8 14 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 e4 b7 fb ff c3 48 83 ec 08 e8 fa 2c 00 00 48 89 04 24 b8 14 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 43 2d 00 00 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f64036aaba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00000000000000e2 RCX: 000000000045c581
RDX: 0000000000000001 RSI: 00007f64036aac00 RDI: 00000000000000f0
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000b7c R14: 00000000004cd906 R15: 000000000076bf2c
---[ end trace 56ea9e8ffeddcc39 ]---