------------[ cut here ]------------ dst_release underflow WARNING: CPU: 1 PID: 13366 at net/core/dst.c:173 dst_release net/core/dst.c:173 [inline] WARNING: CPU: 1 PID: 13366 at net/core/dst.c:173 dst_release+0xd2/0xe0 net/core/dst.c:167 Modules linked in: CPU: 1 PID: 13366 Comm: syz-executor.2 Not tainted 5.16.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dst_release net/core/dst.c:173 [inline] RIP: 0010:dst_release+0xd2/0xe0 net/core/dst.c:167 Code: 89 c3 89 c6 e8 1f 11 48 fa 85 db 74 a4 e9 5b d9 11 02 e8 f1 0e 48 fa 48 c7 c7 60 5d ad 8a c6 05 0b d1 4d 06 01 e8 c5 01 d3 01 <0f> 0b eb c6 66 2e 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55 48 RSP: 0018:ffffc90010d7f860 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815e4328 RDI: fffff520021afefe RBP: ffff88807be62a58 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815de0ce R11: 0000000000000000 R12: ffff88807be62a58 R13: 00000000ffffffff R14: 0000000000000500 R15: ffff88809f4c0000 FS: 00007ff5557e4700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ce1629e190 CR3: 00000000a0945000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: refdst_drop include/net/dst.h:261 [inline] skb_dst_drop include/net/dst.h:273 [inline] skb_release_head_state+0x1fd/0x280 net/core/skbuff.c:726 skb_release_all net/core/skbuff.c:740 [inline] __kfree_skb net/core/skbuff.c:756 [inline] kfree_skb net/core/skbuff.c:774 [inline] kfree_skb+0xfa/0x3f0 net/core/skbuff.c:768 __mptcp_alloc_tx_skb net/mptcp/protocol.c:1200 [inline] mptcp_alloc_tx_skb net/mptcp/protocol.c:1214 [inline] mptcp_sendmsg_frag+0x16b4/0x2190 net/mptcp/protocol.c:1279 __mptcp_push_pending+0x232/0x7a0 net/mptcp/protocol.c:1545 mptcp_sendmsg+0x8c5/0x1220 net/mptcp/protocol.c:1741 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:644 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_write_iter+0x289/0x3c0 net/socket.c:1057 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x429/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x1ee/0x250 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7ff556e6ee99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff5557e4168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff556f81f60 RCX: 00007ff556e6ee99 RDX: 000000000001ff60 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00007ff556ec8ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcf423331f R14: 00007ff5557e4300 R15: 0000000000022000