RDX: 0000000004040845 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Oops: divide error: 0000 [#1] SMP KASAN PTI CPU: 0 UID: 0 PID: 3836 Comm: syz.2.8496 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__tcp_select_window+0x7a2/0x1270 net/ipv4/tcp_output.c:3333 Code: ff ff ff 44 89 e1 d3 e0 89 c1 f7 d1 41 01 ce 41 21 c6 e9 c5 00 00 00 e8 bc ac 01 f8 e9 b8 00 00 00 e8 b2 ac 01 f8 44 89 f0 99 7c 24 2c 41 29 d6 48 bb 00 00 00 00 00 fc ff df e9 9c 00 00 00 RSP: 0018:ffffc90004847380 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88806803dac0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90004847470 R08: ffff88802e901a43 R09: 1ffff11005d20348 R10: dffffc0000000000 R11: ffffed1005d20349 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880a78d24f0 FS: 0000000000000000(0000) GS:ffff888126139000(0063) knlGS:00000000f54d6b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000800000d8 CR3: 00000000a794e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 00000000e08e000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: tcp_select_window net/ipv4/tcp_output.c:280 [inline] __tcp_transmit_skb+0xbc7/0x3aa0 net/ipv4/tcp_output.c:1565 tcp_transmit_skb net/ipv4/tcp_output.c:1646 [inline] tcp_send_active_reset+0x2d1/0x5b0 net/ipv4/tcp_output.c:3828 mptcp_do_fastclose+0x27e/0x380 net/mptcp/protocol.c:2792 mptcp_disconnect+0x238/0x710 net/mptcp/protocol.c:3252 mptcp_sendmsg_fastopen+0x2f8/0x580 net/mptcp/protocol.c:1775 mptcp_sendmsg+0x1774/0x1980 net/mptcp/protocol.c:1854 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0xe5/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg+0x164/0x220 net/socket.c:2716 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fe1539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f54d655c EFLAGS: 00000206 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000680 RDX: 0000000004040845 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__tcp_select_window+0x7a2/0x1270 net/ipv4/tcp_output.c:3333 Code: ff ff ff 44 89 e1 d3 e0 89 c1 f7 d1 41 01 ce 41 21 c6 e9 c5 00 00 00 e8 bc ac 01 f8 e9 b8 00 00 00 e8 b2 ac 01 f8 44 89 f0 99 7c 24 2c 41 29 d6 48 bb 00 00 00 00 00 fc ff df e9 9c 00 00 00 RSP: 0018:ffffc90004847380 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88806803dac0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90004847470 R08: ffff88802e901a43 R09: 1ffff11005d20348 R10: dffffc0000000000 R11: ffffed1005d20349 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880a78d24f0 FS: 0000000000000000(0000) GS:ffff888126239000(0063) knlGS:00000000f54d6b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000031224220 CR3: 00000000a794e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 00000000e08e000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: ff 44 89 e1 incl -0x1f(%rcx,%rcx,4) 4: d3 e0 shl %cl,%eax 6: 89 c1 mov %eax,%ecx 8: f7 d1 not %ecx a: 41 01 ce add %ecx,%r14d d: 41 21 c6 and %eax,%r14d 10: e9 c5 00 00 00 jmp 0xda 15: e8 bc ac 01 f8 call 0xf801acd6 1a: e9 b8 00 00 00 jmp 0xd7 1f: e8 b2 ac 01 f8 call 0xf801acd6 24: 44 89 f0 mov %r14d,%eax 27: 99 cltd * 28: f7 7c 24 2c idivl 0x2c(%rsp) <-- trapping instruction 2c: 41 29 d6 sub %edx,%r14d 2f: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx 36: fc ff df 39: e9 9c 00 00 00 jmp 0xda