------------[ cut here ]------------
TCP recvmsg seq # bug 2: copied 4219BCC6, seq 4219BC8E, rcvnxt 4219BC8F, fl 40
WARNING: CPU: 1 PID: 6610 at net/ipv4/tcp.c:2703 tcp_recvmsg_locked+0x80e/0x3660 net/ipv4/tcp.c:2701
Modules linked in:
CPU: 1 UID: 0 PID: 6610 Comm: syz.0.35 Not tainted 6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:tcp_recvmsg_locked+0x80e/0x3660 net/ipv4/tcp.c:2701
Code: 48 c1 e8 03 42 0f b6 04 28 84 c0 4c 8b 74 24 18 0f 85 35 01 00 00 8b 0f 48 c7 c7 20 17 9d 8c 44 8b 44 24 3c e8 a3 40 9b f7 90 <0f> 0b 90 90 e9 40 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 10
RSP: 0018:ffffc90003207240 EFLAGS: 00010246
RAX: 324760eda4bb6500 RBX: 0000000000000000 RCX: ffff888033f58000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90003207610 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1ec R12: ffff888033c88d70
R13: dffffc0000000000 R14: ffff888032fcf3a8 R15: ffff888033c88d98
FS:  00007fa6651436c0(0000) GS:ffff888125d5a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0027ee000 CR3: 000000007b578000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 receive_fallback_to_copy net/ipv4/tcp.c:1945 [inline]
 tcp_zerocopy_receive+0x800/0x21d0 net/ipv4/tcp.c:2177
 do_tcp_getsockopt+0x1dd0/0x2660 net/ipv4/tcp.c:4665
 tcp_getsockopt+0x83/0x130 net/ipv4/tcp.c:4764
 do_sock_getsockopt+0x372/0x450 net/socket.c:2405
 __sys_getsockopt net/socket.c:2434 [inline]
 __do_sys_getsockopt net/socket.c:2441 [inline]
 __se_sys_getsockopt net/socket.c:2438 [inline]
 __x64_sys_getsockopt+0x1a5/0x250 net/socket.c:2438
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa66437e819
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa665143038 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007fa664535fa0 RCX: 00007fa66437e819
RDX: 0000000000000023 RSI: 0000000000000006 RDI: 0000000000000003
RBP: 00007fa6643f175e R08: 00000000200004c0 R09: 0000000000000000
R10: 0000000020000380 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa664535fa0 R15: 00007fff68992458
 </TASK>