r0 = syz_open_procfs(0x0, &(0x7f0000000040)='net/ip_mr_cache\x00')
preadv(r0, &(0x7f00000000c0)=[{&(0x7f00000004c0)=""/4096, 0x1000}], 0x1, 0xffff, 0x0)