================================================================== BUG: KASAN: use-after-free in ether_addr_equal_64bits include/linux/etherdevice.h:348 [inline] BUG: KASAN: use-after-free in eth_type_trans+0x6ce/0x760 net/ethernet/eth.c:167 Read of size 8 at addr ffff888084bf0040 by task syz-executor336/10162 CPU: 1 PID: 10162 Comm: syz-executor336 Not tainted 5.5.0-rc2-syzkaller #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+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 ether_addr_equal_64bits include/linux/etherdevice.h:348 [inline] eth_type_trans+0x6ce/0x760 net/ethernet/eth.c:167 napi_frags_finish net/core/dev.c:5924 [inline] napi_gro_frags+0x8c2/0xd00 net/core/dev.c:5999 tun_get_user+0x2e7f/0x3fc0 drivers/net/tun.c:1976 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2022 call_write_iter include/linux/fs.h:1902 [inline] do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x184/0x610 fs/read_write.c:951 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1015 do_writev+0x15b/0x330 fs/read_write.c:1058 __do_sys_writev fs/read_write.c:1131 [inline] __se_sys_writev fs/read_write.c:1128 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1128 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441800 Code: 05 48 3d 01 f0 ff ff 0f 83 fd 0e fc ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 51 9c 29 00 00 75 14 b8 14 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 d4 0e fc ff c3 48 83 ec 08 e8 9a 2b 00 00 RSP: 002b:00007ffe7bc617c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441800 RDX: 0000000000000001 RSI: 00007ffe7bc61820 RDI: 00000000000000f0 RBP: 00007ffe7bc617f0 R08: 0000000000000000 R09: 0000000000000020 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000004 R14: 00007ffe7bc61870 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea000212fc00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 raw: 00fffe0000000000 ffffea000212fc08 ffffea000212fc08 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888084beff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888084beff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888084bf0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888084bf0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888084bf0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================