report

==================================================================
BUG: KASAN: slab-use-after-free in compare_netdev_and_ip drivers/infiniband/core/cma.c:473 [inline]
BUG: KASAN: slab-use-after-free in cma_add_id_to_tree drivers/infiniband/core/cma.c:513 [inline]
BUG: KASAN: slab-use-after-free in rdma_resolve_route+0x2524/0x32a0 drivers/infiniband/core/cma.c:3379
Read of size 4 at addr ffff88803bec8184 by task syz-executor.0/20220

CPU: 3 PID: 20220 Comm: syz-executor.0 Not tainted 6.8.0-rc4-next-20240214 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x250/0x380 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 compare_netdev_and_ip drivers/infiniband/core/cma.c:473 [inline]
 cma_add_id_to_tree drivers/infiniband/core/cma.c:513 [inline]
 rdma_resolve_route+0x2524/0x32a0 drivers/infiniband/core/cma.c:3379
 ucma_resolve_route+0x1c3/0x330 drivers/infiniband/core/ucma.c:745
 ucma_write+0x2f0/0x440 drivers/infiniband/core/ucma.c:1743
 vfs_write+0x2b3/0xcf0 fs/read_write.c:588
 ksys_write+0x18e/0x2d0 fs/read_write.c:643
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fe6e4e7dde9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe6e5bc40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe6e4fabf80 RCX: 00007fe6e4e7dde9
RDX: 0000000000000010 RSI: 0000000020000440 RDI: 0000000000000003
RBP: 00007fe6e4eca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fe6e4fabf80 R15: 00007ffcf1ec8948
 </TASK>

Allocated by task 20217:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace+0x1d9/0x360 mm/slub.c:4013
 kmalloc include/linux/slab.h:590 [inline]
 kzalloc include/linux/slab.h:711 [inline]
 __rdma_create_id+0x6a/0x5a0 drivers/infiniband/core/cma.c:993
 rdma_create_user_id+0x88/0xd0 drivers/infiniband/core/cma.c:1049
 ucma_create_id+0x2e1/0x520 drivers/infiniband/core/ucma.c:463
 ucma_write+0x2f0/0x440 drivers/infiniband/core/ucma.c:1743
 vfs_write+0x2b3/0xcf0 fs/read_write.c:588
 ksys_write+0x18e/0x2d0 fs/read_write.c:643
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Freed by task 20216:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:586
 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2122 [inline]
 slab_free mm/slub.c:4296 [inline]
 kfree+0x14a/0x380 mm/slub.c:4406
 ucma_close_id drivers/infiniband/core/ucma.c:186 [inline]
 ucma_destroy_private_ctx+0x162/0xc70 drivers/infiniband/core/ucma.c:578
 ucma_close+0x103/0x180 drivers/infiniband/core/ucma.c:1808
 __fput+0x442/0x8d0 fs/file_table.c:411
 __do_sys_close fs/open.c:1557 [inline]
 __se_sys_close fs/open.c:1542 [inline]
 __x64_sys_close+0x84/0x120 fs/open.c:1542
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

The buggy address belongs to the object at ffff88803bec8000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 388 bytes inside of
 freed 2048-byte region [ffff88803bec8000, ffff88803bec8800)

The buggy address belongs to the physical page:
page:ffffea0000efb200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3bec8
head:ffffea0000efb200 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000840 ffff888015042f00 ffffea00006ae600 dead000000000002
raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 8202, tgid 8202 (syz-executor.2), ts 163667417341, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
 prep_new_page mm/page_alloc.c:1540 [inline]
 get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
 __alloc_pages+0x256/0x6a0 mm/page_alloc.c:4567
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2191
 allocate_slab mm/slub.c:2354 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2407
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3541
 __slab_alloc mm/slub.c:3626 [inline]
 __slab_alloc_node mm/slub.c:3679 [inline]
 slab_alloc_node mm/slub.c:3851 [inline]
 __do_kmalloc_node mm/slub.c:3981 [inline]
 __kmalloc_node_track_caller+0x2d4/0x4e0 mm/slub.c:4002
 kmalloc_reserve+0xfd/0x250 net/core/skbuff.c:582
 pskb_expand_head+0x209/0x13a0 net/core/skbuff.c:2136
 netlink_trim+0x192/0x230 net/netlink/af_netlink.c:1323
 netlink_broadcast_filtered+0x7b/0x1300 net/netlink/af_netlink.c:1529
 nlmsg_multicast_filtered include/net/netlink.h:1111 [inline]
 nlmsg_multicast include/net/netlink.h:1130 [inline]
 nlmsg_notify+0x104/0x1d0 net/netlink/af_netlink.c:2586
 __dev_notify_flags+0xfe/0x410 net/core/dev.c:8720
 dev_change_flags+0xf7/0x1a0 net/core/dev.c:8762
 do_setlink+0xd12/0x43f0 net/core/rtnetlink.c:2897
 __rtnl_newlink net/core/rtnetlink.c:3695 [inline]
 rtnl_newlink+0x18bc/0x2170 net/core/rtnetlink.c:3742
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88803bec8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803bec8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803bec8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88803bec8200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803bec8280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

repro.c

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <netinet/in.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/capability.h>
#include <linux/genetlink.h>
#include <linux/if_addr.h>
#include <linux/if_ether.h>
#include <linux/if_link.h>
#include <linux/if_tun.h>
#include <linux/in6.h>
#include <linux/ip.h>
#include <linux/neighbour.h>
#include <linux/net.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/tcp.h>
#include <linux/veth.h>

static void sleep_ms(uint64_t ms) {
  usleep(ms * 1000);
}

static uint64_t current_time_ms(void) {
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static bool write_file(const char* file, const char* what, ...) {
  char buf[1024];
  va_list args;
  va_start(args, what);
  vsnprintf(buf, sizeof(buf), what, args);
  va_end(args);
  buf[sizeof(buf) - 1] = 0;
  int len = strlen(buf);
  int fd = open(file, O_WRONLY | O_CLOEXEC);
  if (fd == -1)
    return false;
  if (write(fd, buf, len) != len) {
    int err = errno;
    close(fd);
    errno = err;
    return false;
  }
  close(fd);
  return true;
}

struct nlmsg {
  char* pos;
  int nesting;
  struct nlattr* nested[8];
  char buf[4096];
};

static void netlink_init(struct nlmsg* nlmsg,
                         int typ,
                         int flags,
                         const void* data,
                         int size) {
  memset(nlmsg, 0, sizeof(*nlmsg));
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_type = typ;
  hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
  memcpy(hdr + 1, data, size);
  nlmsg->pos = (char*)(hdr + 1) + NLMSG_ALIGN(size);
}

static void netlink_attr(struct nlmsg* nlmsg,
                         int typ,
                         const void* data,
                         int size) {
  struct nlattr* attr = (struct nlattr*)nlmsg->pos;
  attr->nla_len = sizeof(*attr) + size;
  attr->nla_type = typ;
  if (size > 0)
    memcpy(attr + 1, data, size);
  nlmsg->pos += NLMSG_ALIGN(attr->nla_len);
}

static int netlink_send_ext(struct nlmsg* nlmsg,
                            int sock,
                            uint16_t reply_type,
                            int* reply_len,
                            bool dofail) {
  if (nlmsg->pos > nlmsg->buf + sizeof(nlmsg->buf) || nlmsg->nesting)
    exit(1);
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_len = nlmsg->pos - nlmsg->buf;
  struct sockaddr_nl addr;
  memset(&addr, 0, sizeof(addr));
  addr.nl_family = AF_NETLINK;
  ssize_t n = sendto(sock, nlmsg->buf, hdr->nlmsg_len, 0,
                     (struct sockaddr*)&addr, sizeof(addr));
  if (n != (ssize_t)hdr->nlmsg_len) {
    if (dofail)
      exit(1);
    return -1;
  }
  n = recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  if (reply_len)
    *reply_len = 0;
  if (n < 0) {
    if (dofail)
      exit(1);
    return -1;
  }
  if (n < (ssize_t)sizeof(struct nlmsghdr)) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type == NLMSG_DONE)
    return 0;
  if (reply_len && hdr->nlmsg_type == reply_type) {
    *reply_len = n;
    return 0;
  }
  if (n < (ssize_t)(sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr))) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type != NLMSG_ERROR) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  errno = -((struct nlmsgerr*)(hdr + 1))->error;
  return -errno;
}

static int netlink_send(struct nlmsg* nlmsg, int sock) {
  return netlink_send_ext(nlmsg, sock, 0, NULL, true);
}

static int netlink_query_family_id(struct nlmsg* nlmsg,
                                   int sock,
                                   const char* family_name,
                                   bool dofail) {
  struct genlmsghdr genlhdr;
  memset(&genlhdr, 0, sizeof(genlhdr));
  genlhdr.cmd = CTRL_CMD_GETFAMILY;
  netlink_init(nlmsg, GENL_ID_CTRL, 0, &genlhdr, sizeof(genlhdr));
  netlink_attr(nlmsg, CTRL_ATTR_FAMILY_NAME, family_name,
               strnlen(family_name, GENL_NAMSIZ - 1) + 1);
  int n = 0;
  int err = netlink_send_ext(nlmsg, sock, GENL_ID_CTRL, &n, dofail);
  if (err < 0) {
    return -1;
  }
  uint16_t id = 0;
  struct nlattr* attr = (struct nlattr*)(nlmsg->buf + NLMSG_HDRLEN +
                                         NLMSG_ALIGN(sizeof(genlhdr)));
  for (; (char*)attr < nlmsg->buf + n;
       attr = (struct nlattr*)((char*)attr + NLMSG_ALIGN(attr->nla_len))) {
    if (attr->nla_type == CTRL_ATTR_FAMILY_ID) {
      id = *(uint16_t*)(attr + 1);
      break;
    }
  }
  if (!id) {
    errno = EINVAL;
    return -1;
  }
  recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  return id;
}

static void netlink_device_change(struct nlmsg* nlmsg,
                                  int sock,
                                  const char* name,
                                  bool up,
                                  const char* master,
                                  const void* mac,
                                  int macsize,
                                  const char* new_name) {
  struct ifinfomsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  if (up)
    hdr.ifi_flags = hdr.ifi_change = IFF_UP;
  hdr.ifi_index = if_nametoindex(name);
  netlink_init(nlmsg, RTM_NEWLINK, 0, &hdr, sizeof(hdr));
  if (new_name)
    netlink_attr(nlmsg, IFLA_IFNAME, new_name, strlen(new_name));
  if (master) {
    int ifindex = if_nametoindex(master);
    netlink_attr(nlmsg, IFLA_MASTER, &ifindex, sizeof(ifindex));
  }
  if (macsize)
    netlink_attr(nlmsg, IFLA_ADDRESS, mac, macsize);
  int err = netlink_send(nlmsg, sock);
  if (err < 0) {
  }
}

static int netlink_add_addr(struct nlmsg* nlmsg,
                            int sock,
                            const char* dev,
                            const void* addr,
                            int addrsize) {
  struct ifaddrmsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  hdr.ifa_family = addrsize == 4 ? AF_INET : AF_INET6;
  hdr.ifa_prefixlen = addrsize == 4 ? 24 : 120;
  hdr.ifa_scope = RT_SCOPE_UNIVERSE;
  hdr.ifa_index = if_nametoindex(dev);
  netlink_init(nlmsg, RTM_NEWADDR, NLM_F_CREATE | NLM_F_REPLACE, &hdr,
               sizeof(hdr));
  netlink_attr(nlmsg, IFA_LOCAL, addr, addrsize);
  netlink_attr(nlmsg, IFA_ADDRESS, addr, addrsize);
  return netlink_send(nlmsg, sock);
}

static void netlink_add_addr4(struct nlmsg* nlmsg,
                              int sock,
                              const char* dev,
                              const char* addr) {
  struct in_addr in_addr;
  inet_pton(AF_INET, addr, &in_addr);
  int err = netlink_add_addr(nlmsg, sock, dev, &in_addr, sizeof(in_addr));
  if (err < 0) {
  }
}

static void netlink_add_addr6(struct nlmsg* nlmsg,
                              int sock,
                              const char* dev,
                              const char* addr) {
  struct in6_addr in6_addr;
  inet_pton(AF_INET6, addr, &in6_addr);
  int err = netlink_add_addr(nlmsg, sock, dev, &in6_addr, sizeof(in6_addr));
  if (err < 0) {
  }
}

static void netlink_add_neigh(struct nlmsg* nlmsg,
                              int sock,
                              const char* name,
                              const void* addr,
                              int addrsize,
                              const void* mac,
                              int macsize) {
  struct ndmsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  hdr.ndm_family = addrsize == 4 ? AF_INET : AF_INET6;
  hdr.ndm_ifindex = if_nametoindex(name);
  hdr.ndm_state = NUD_PERMANENT;
  netlink_init(nlmsg, RTM_NEWNEIGH, NLM_F_EXCL | NLM_F_CREATE, &hdr,
               sizeof(hdr));
  netlink_attr(nlmsg, NDA_DST, addr, addrsize);
  netlink_attr(nlmsg, NDA_LLADDR, mac, macsize);
  int err = netlink_send(nlmsg, sock);
  if (err < 0) {
  }
}

static struct nlmsg nlmsg;

static int tunfd = -1;

#define TUN_IFACE "syz_tun"
#define LOCAL_MAC 0xaaaaaaaaaaaa
#define REMOTE_MAC 0xaaaaaaaaaabb
#define LOCAL_IPV4 "172.20.20.170"
#define REMOTE_IPV4 "172.20.20.187"
#define LOCAL_IPV6 "fe80::aa"
#define REMOTE_IPV6 "fe80::bb"

#define IFF_NAPI 0x0010

static void initialize_tun(void) {
  tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
  if (tunfd == -1) {
    printf("tun: can't open /dev/net/tun: please enable CONFIG_TUN=y\n");
    printf("otherwise fuzzing or reproducing might not work as intended\n");
    return;
  }
  const int kTunFd = 200;
  if (dup2(tunfd, kTunFd) < 0)
    exit(1);
  close(tunfd);
  tunfd = kTunFd;
  struct ifreq ifr;
  memset(&ifr, 0, sizeof(ifr));
  strncpy(ifr.ifr_name, TUN_IFACE, IFNAMSIZ);
  ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) {
    exit(1);
  }
  char sysctl[64];
  sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/accept_dad", TUN_IFACE);
  write_file(sysctl, "0");
  sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/router_solicitations", TUN_IFACE);
  write_file(sysctl, "0");
  int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
  if (sock == -1)
    exit(1);
  netlink_add_addr4(&nlmsg, sock, TUN_IFACE, LOCAL_IPV4);
  netlink_add_addr6(&nlmsg, sock, TUN_IFACE, LOCAL_IPV6);
  uint64_t macaddr = REMOTE_MAC;
  struct in_addr in_addr;
  inet_pton(AF_INET, REMOTE_IPV4, &in_addr);
  netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in_addr, sizeof(in_addr),
                    &macaddr, ETH_ALEN);
  struct in6_addr in6_addr;
  inet_pton(AF_INET6, REMOTE_IPV6, &in6_addr);
  netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in6_addr, sizeof(in6_addr),
                    &macaddr, ETH_ALEN);
  macaddr = LOCAL_MAC;
  netlink_device_change(&nlmsg, sock, TUN_IFACE, true, 0, &macaddr, ETH_ALEN,
                        NULL);
  close(sock);
}

static int read_tun(char* data, int size) {
  if (tunfd < 0)
    return -1;
  int rv = read(tunfd, data, size);
  if (rv < 0) {
    if (errno == EAGAIN || errno == EBADFD)
      return -1;
    exit(1);
  }
  return rv;
}

static void flush_tun() {
  char data[1000];
  while (read_tun(&data[0], sizeof(data)) != -1) {
  }
}

#define MAX_FDS 30

static void setup_common() {
  if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) {
  }
}

static void setup_binderfs() {
  if (mkdir("/dev/binderfs", 0777)) {
  }
  if (mount("binder", "/dev/binderfs", "binder", 0, NULL)) {
  }
  if (symlink("/dev/binderfs", "./binderfs")) {
  }
}

static void loop();

static void sandbox_common() {
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setsid();
  struct rlimit rlim;
  rlim.rlim_cur = rlim.rlim_max = (200 << 20);
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 32 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 136 << 20;
  setrlimit(RLIMIT_FSIZE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_STACK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 128 << 20;
  setrlimit(RLIMIT_CORE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 256;
  setrlimit(RLIMIT_NOFILE, &rlim);
  if (unshare(CLONE_NEWNS)) {
  }
  if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
  typedef struct {
    const char* name;
    const char* value;
  } sysctl_t;
  static const sysctl_t sysctls[] = {
      {"/proc/sys/kernel/shmmax", "16777216"},
      {"/proc/sys/kernel/shmall", "536870912"},
      {"/proc/sys/kernel/shmmni", "1024"},
      {"/proc/sys/kernel/msgmax", "8192"},
      {"/proc/sys/kernel/msgmni", "1024"},
      {"/proc/sys/kernel/msgmnb", "1024"},
      {"/proc/sys/kernel/sem", "1024 1048576 500 1024"},
  };
  unsigned i;
  for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++)
    write_file(sysctls[i].name, sysctls[i].value);
}

static int wait_for_loop(int pid) {
  if (pid < 0)
    exit(1);
  int status = 0;
  while (waitpid(-1, &status, __WALL) != pid) {
  }
  return WEXITSTATUS(status);
}

static void drop_caps(void) {
  struct __user_cap_header_struct cap_hdr = {};
  struct __user_cap_data_struct cap_data[2] = {};
  cap_hdr.version = _LINUX_CAPABILITY_VERSION_3;
  cap_hdr.pid = getpid();
  if (syscall(SYS_capget, &cap_hdr, &cap_data))
    exit(1);
  const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE);
  cap_data[0].effective &= ~drop;
  cap_data[0].permitted &= ~drop;
  cap_data[0].inheritable &= ~drop;
  if (syscall(SYS_capset, &cap_hdr, &cap_data))
    exit(1);
}

static int do_sandbox_none(void) {
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid != 0)
    return wait_for_loop(pid);
  setup_common();
  sandbox_common();
  drop_caps();
  if (unshare(CLONE_NEWNET)) {
  }
  write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535");
  initialize_tun();
  setup_binderfs();
  loop();
  exit(1);
}

static void kill_and_wait(int pid, int* status) {
  kill(-pid, SIGKILL);
  kill(pid, SIGKILL);
  for (int i = 0; i < 100; i++) {
    if (waitpid(-1, status, WNOHANG | __WALL) == pid)
      return;
    usleep(1000);
  }
  DIR* dir = opendir("/sys/fs/fuse/connections");
  if (dir) {
    for (;;) {
      struct dirent* ent = readdir(dir);
      if (!ent)
        break;
      if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
        continue;
      char abort[300];
      snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort",
               ent->d_name);
      int fd = open(abort, O_WRONLY);
      if (fd == -1) {
        continue;
      }
      if (write(fd, abort, 1) < 0) {
      }
      close(fd);
    }
    closedir(dir);
  } else {
  }
  while (waitpid(-1, status, __WALL) != pid) {
  }
}

static void setup_test() {
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  write_file("/proc/self/oom_score_adj", "1000");
  flush_tun();
}

static void close_fds() {
  for (int fd = 3; fd < MAX_FDS; fd++)
    close(fd);
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void) {
  int iter = 0;
  for (;; iter++) {
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      setup_test();
      execute_one();
      close_fds();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      sleep_ms(1);
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff};

void execute_one(void) {
  intptr_t res = 0;
  res = syscall(__NR_socket, /*domain=*/0x10ul, /*type=*/3ul, /*proto=*/0x14);
  if (res != -1)
    r[0] = res;
  *(uint64_t*)0x20000180 = 0;
  *(uint32_t*)0x20000188 = 0;
  *(uint64_t*)0x20000190 = 0x20000140;
  *(uint64_t*)0x20000140 = 0x20000080;
  *(uint32_t*)0x20000080 = 0x38;
  *(uint16_t*)0x20000084 = 0x1403;
  *(uint16_t*)0x20000086 = 1;
  *(uint32_t*)0x20000088 = 0;
  *(uint32_t*)0x2000008c = 0;
  *(uint16_t*)0x20000090 = 9;
  *(uint16_t*)0x20000092 = 2;
  memcpy((void*)0x20000094, "syz1\000", 5);
  *(uint16_t*)0x2000009c = 8;
  *(uint16_t*)0x2000009e = 0x41;
  memcpy((void*)0x200000a0, "rxe\000", 4);
  *(uint16_t*)0x200000a4 = 0x14;
  *(uint16_t*)0x200000a6 = 0x33;
  memcpy((void*)0x200000a8, "syz_tun\000\000\000\000\000\000\000\000\000", 16);
  *(uint64_t*)0x20000148 = 0x38;
  *(uint64_t*)0x20000198 = 1;
  *(uint64_t*)0x200001a0 = 0;
  *(uint64_t*)0x200001a8 = 0;
  *(uint32_t*)0x200001b0 = 0;
  syscall(__NR_sendmsg, /*fd=*/r[0], /*msg=*/0x20000180ul, /*f=*/0ul);
  memcpy((void*)0x20000100, "/dev/infiniband/rdma_cm\000", 24);
  res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000100ul,
                /*flags=*/2ul, /*mode=*/0ul);
  if (res != -1)
    r[1] = res;
  *(uint32_t*)0x20000080 = 0;
  *(uint16_t*)0x20000084 = 0x18;
  *(uint16_t*)0x20000086 = 0xfa00;
  *(uint64_t*)0x20000088 = 0;
  *(uint64_t*)0x20000090 = 0x200000c0;
  *(uint16_t*)0x20000098 = 0x106;
  *(uint8_t*)0x2000009a = 0;
  memset((void*)0x2000009b, 0, 5);
  res = syscall(__NR_write, /*fd=*/r[1], /*data=*/0x20000080ul, /*len=*/0x20ul);
  if (res != -1)
    r[2] = *(uint32_t*)0x200000c0;
  *(uint32_t*)0x200003c0 = 3;
  *(uint16_t*)0x200003c4 = 0x40;
  *(uint16_t*)0x200003c6 = 0xfa00;
  *(uint16_t*)0x200003c8 = 0xa;
  *(uint16_t*)0x200003ca = htobe16(0x4e24);
  *(uint32_t*)0x200003cc = htobe32(1);
  *(uint8_t*)0x200003d0 = -1;
  *(uint8_t*)0x200003d1 = 2;
  memset((void*)0x200003d2, 0, 13);
  *(uint8_t*)0x200003df = 1;
  *(uint32_t*)0x200003e0 = 9;
  *(uint16_t*)0x200003e4 = 0xa;
  *(uint16_t*)0x200003e6 = htobe16(0);
  *(uint32_t*)0x200003e8 = htobe32(6);
  *(uint8_t*)0x200003ec = 0xfe;
  *(uint8_t*)0x200003ed = 0x80;
  memset((void*)0x200003ee, 0, 13);
  *(uint8_t*)0x200003fb = 0xbb;
  *(uint32_t*)0x200003fc = 0xfffff000;
  *(uint32_t*)0x20000400 = r[2];
  *(uint32_t*)0x20000404 = 2;
  syscall(__NR_write, /*fd=*/r[1], /*data=*/0x200003c0ul, /*len=*/0x48ul);
  *(uint32_t*)0x20000140 = 0x15;
  *(uint16_t*)0x20000144 = 0x110;
  *(uint16_t*)0x20000146 = 0xfa00;
  *(uint32_t*)0x20000148 = r[2];
  *(uint32_t*)0x2000014c = 0;
  *(uint16_t*)0x20000150 = 0;
  *(uint16_t*)0x20000152 = 0x30;
  *(uint32_t*)0x20000154 = 0;
  *(uint16_t*)0x20000158 = 0x1b;
  *(uint16_t*)0x2000015a = htobe16(0);
  *(uint32_t*)0x2000015c = htobe32(0);
  memset((void*)0x20000160, 0, 16);
  *(uint32_t*)0x20000170 = 0;
  *(uint16_t*)0x200001d8 = 0x1b;
  *(uint16_t*)0x200001da = htobe16(0);
  *(uint32_t*)0x200001dc = htobe32(0);
  memset((void*)0x200001e0, 0, 16);
  *(uint64_t*)0x200001f0 = htobe64(0);
  *(uint64_t*)0x200001f8 = htobe64(0);
  *(uint64_t*)0x20000200 = 0;
  syscall(__NR_write, /*fd=*/r[1], /*data=*/0x20000140ul, /*len=*/0x118ul);
  *(uint32_t*)0x20000440 = 4;
  *(uint16_t*)0x20000444 = 8;
  *(uint16_t*)0x20000446 = 0xfa00;
  *(uint32_t*)0x20000448 = r[2];
  *(uint32_t*)0x2000044c = 0xffff741a;
  syscall(__NR_write, /*fd=*/r[1], /*data=*/0x20000440ul, /*len=*/0x10ul);
}
int main(void) {
  syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  do_sandbox_none();
  return 0;
}

repro.txt

r0 = socket$nl_rdma(0x10, 0x3, 0x14)
sendmsg$RDMA_NLDEV_CMD_NEWLINK(r0, &(0x7f0000000180)={0x0, 0x0, &(0x7f0000000140)={&(0x7f0000000080)={0x38, 0x1403, 0x1, 0x0, 0x0, "", [{{0x9, 0x2, 'syz1\x00'}, {0x8, 0x41, 'rxe\x00'}, {0x14, 0x33, 'syz_tun\x00'}}]}, 0x38}}, 0x0)
r1 = openat$rdma_cm(0xffffffffffffff9c, &(0x7f0000000100), 0x2, 0x0)
write$RDMA_USER_CM_CMD_CREATE_ID(r1, &(0x7f0000000080)={0x0, 0x18, 0xfa00, {0x0, &(0x7f00000000c0)={<r2=>0xffffffffffffffff}, 0x106}}, 0x20)
write$RDMA_USER_CM_CMD_RESOLVE_IP(r1, &(0x7f00000003c0)={0x3, 0x40, 0xfa00, {{0xa, 0x4e24, 0x1, @mcast2, 0x9}, {0xa, 0x0, 0x6, @remote, 0xfffff000}, r2, 0x2}}, 0x48)
write$RDMA_USER_CM_CMD_RESOLVE_ADDR(r1, &(0x7f0000000140)={0x15, 0x110, 0xfa00, {r2, 0x0, 0x0, 0x30, 0x0, @in6={0x1b, 0x0, 0x0, @empty}, @ib}}, 0x118)
write$RDMA_USER_CM_CMD_RESOLVE_ROUTE(r1, &(0x7f0000000440)={0x4, 0x8, 0xfa00, {r2, 0xffff741a}}, 0x10)