------------[ cut here ]------------
n > v || v > page_size(head)
WARNING: lib/iov_iter.c:356 at copy_page_to_iter+0x2df/0x340, CPU#0: syz.2.1053/10453
Modules linked in:
CPU: 0 UID: 0 PID: 10453 Comm: syz.2.1053 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:copy_page_to_iter+0x2df/0x340
Code: 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 40 6a 15 fd 90 0f 0b 90 45 31 ed eb db e8 32 6a 15 fd 90 <0f> 0b 90 45 31 ed eb cd 44 89 e9 80 e1 07 38 c1 0f 8c af fe ff ff
RSP: 0018:ffffc90007237560 EFLAGS: 00010293

RAX: ffffffff84b05a8e RBX: 000000000000022e RCX: ffff8881736fd880
RDX: 0000000000000000 RSI: 000000000000022e RDI: ffffffffffffff6c
RBP: ffffea0006c41040 R08: ffffffff903135f7 R09: 1ffffffff20626be
R10: dffffc0000000000 R11: fffffbfff20626bf R12: ffffea0006c41040
R13: 000000000000022e R14: ffffffffffffff6c R15: 00000000000002c2
FS:  00007f59f65866c0(0000) GS:ffff88818dc76000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 00000001ae574000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __sk_msg_recvmsg+0x33b/0xfc0
 udp_bpf_recvmsg+0x196/0xac0
 sock_recvmsg+0x155/0x1b0
 ____sys_recvmsg+0x1e6/0x4a0
