ip6_tunnel: ip6gre1 xmit: Local address not yet configured! ================================================================== BUG: KASAN: use-after-free in __tcp_hdrlen include/linux/tcp.h:31 [inline] BUG: KASAN: use-after-free in qdisc_pkt_len_segs_init+0x7f8/0xa30 net/core/dev.c:4140 Read of size 2 at addr ffff88817cf82774 by task syz.2.8352/5349 CPU: 0 UID: 0 PID: 5349 Comm: syz.2.8352 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __tcp_hdrlen include/linux/tcp.h:31 [inline] qdisc_pkt_len_segs_init+0x7f8/0xa30 net/core/dev.c:4140 __dev_queue_xmit+0x29a/0x3950 net/core/dev.c:4782 dev_queue_xmit include/linux/netdevice.h:3418 [inline] hsr_xmit net/hsr/hsr_forward.c:440 [inline] hsr_forward_do net/hsr/hsr_forward.c:581 [inline] hsr_forward_skb+0x167e/0x2ab0 net/hsr/hsr_forward.c:743 hsr_handle_frame+0x6b8/0xa50 net/hsr/hsr_slave.c:81 __netif_receive_skb_core+0x98f/0x3170 net/core/dev.c:6089 __netif_receive_skb_list_core+0x24d/0x810 net/core/dev.c:6277 __netif_receive_skb_list net/core/dev.c:6344 [inline] netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6435 gro_normal_list include/net/gro.h:523 [inline] gro_flush_normal include/net/gro.h:531 [inline] napi_complete_done+0x299/0x730 net/core/dev.c:6803 gro_cell_poll+0x5a9/0x5d0 net/core/gro_cells.c:74 __napi_poll+0xae/0x340 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7953 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] tun_rx_batched+0x617/0x790 drivers/net/tun.c:-1 tun_get_user+0x2bbc/0x43e0 drivers/net/tun.c:1955 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:2001 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3be299ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3be3862028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3be2c16090 RCX: 00007f3be299ce59 RDX: 000000000000007a RSI: 00002000000004c0 RDI: 0000000000000003 RBP: 00007f3be2a32d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3be2c16128 R14: 00007f3be2c16090 R15: 00007ffc7a443918 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x17cf82 flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000000000 ffffea0005f3e088 ffffea0005f3e088 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner info is not present (never set?) Memory state around the buggy address: ffff88817cf82600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88817cf82680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88817cf82700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88817cf82780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88817cf82800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================