------------[ cut here ]------------
WARNING: net/core/skbuff.c:7243 at skb_attempt_defer_free+0x572/0x6d0 net/core/skbuff.c:7243, CPU#1: syz.4.6550/26535
Modules linked in:
CPU: 1 UID: 0 PID: 26535 Comm: syz.4.6550 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:skb_attempt_defer_free+0x572/0x6d0 net/core/skbuff.c:7243
Code: ff e8 72 c4 8f f8 90 0f 0b 90 e9 a8 fb ff ff e8 64 c4 8f f8 eb 85 e8 5d c4 8f f8 90 0f 0b 90 e9 94 fc ff ff e8 4f c4 8f f8 90 <0f> 0b 90 e9 af fc ff ff e8 41 c4 8f f8 90 0f 0b 90 e9 da fc ff ff
RSP: 0018:ffffc9000c427400 EFLAGS: 00010287
RAX: ffffffff8931ee01 RBX: ffff888044538a00 RCX: 0000000000080000
RDX: ffffc90010e1a000 RSI: 0000000000011bb6 RDI: 0000000000011bb7
RBP: ffffc9000c4274b0 R08: ffffffff8f822177 R09: 1ffffffff1f0442e
R10: dffffc0000000000 R11: fffffbfff1f0442f R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888044538a60
FS:  00007f2ca73d56c0(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0979639f98 CR3: 0000000069130000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 udp_recvmsg+0xdb0/0x1050 net/ipv4/udp.c:2145
 sk_udp_recvmsg net/ipv4/udp_bpf.c:-1 [inline]
 udp_bpf_recvmsg+0xb84/0xda0 net/ipv4/udp_bpf.c:-1
 inet_recvmsg+0x24a/0x250 net/ipv4/af_inet.c:891
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 sock_recvmsg+0x1a8/0x270 net/socket.c:1100
 ____sys_recvmsg+0x1c9/0x460 net/socket.c:2812
 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2854
 do_recvmmsg+0x307/0x770 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3039
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ca918f749
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:00007f2ca73d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f2ca93e6090 RCX: 00007f2ca918f749
RDX: 0000000000000001 RSI: 00002000000047c0 RDI: 0000000000000003
RBP: 00007f2ca9213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2ca93e6128 R14: 00007f2ca93e6090 R15: 00007fffd656cdc8
 </TASK>