WARNING in drm_mode_create_lease_ioctl

["Ubisectech Sirius" <bugreport@ubisectech.com>]

[-- Attachment #1: Type: text/plain, Size: 3122 bytes --]

Hello.
We are Ubisectech Sirius Team, the vulnerability lab of China ValiantSec. Recently, our team has discovered a issue in Linux kernel 6.8.  Attached to the email were a PoC file of the issue.

Stack dump:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 18929 at mm/page_alloc.c:4545 __alloc_pages+0x402/0x21b0 mm/page_alloc.c:4545
Modules linked in:
CPU: 1 PID: 18929 Comm: syz-executor.3 Not tainted 6.8.0 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:__alloc_pages+0x402/0x21b0 mm/page_alloc.c:4545
Code: ff 00 0f 84 15 fe ff ff 80 ce 01 e9 0d fe ff ff 83 fe 0a 0f 86 0e fd ff ff 80 3d c7 cf 6a 0d 00 75 0b c6 05 be cf 6a 0d 01 90 <0f> 0b 90 45 31 e4 e9 87 fe ff ff e8 5e 3e 9b ff 84 c0 0f 85 7a fe
RSP: 0018:ffffc90001cc7808 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff92000398f14
RDX: 0000000000000001 RSI: 000000000000000b RDI: 0000000000040dc0
RBP: ffffc90001cc7ab8 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000007a1200
R13: 000000000000000b R14: 0000000000040dc0 R15: 000000000000000b
FS:  00007f1717ba5640(0000) GS:ffff88807ec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000203d0000 CR3: 000000001f5c0000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 __kmalloc_large_node+0x88/0x1a0 mm/slub.c:3926
 __do_kmalloc_node mm/slub.c:3969 [inline]
 __kmalloc+0x370/0x480 mm/slub.c:3994
 kmalloc_array include/linux/slab.h:627 [inline]
 kcalloc include/linux/slab.h:658 [inline]
 fill_object_idr drivers/gpu/drm/drm_lease.c:389 [inline]
 drm_mode_create_lease_ioctl+0x4ca/0x1f70 drivers/gpu/drm/drm_lease.c:522
 drm_ioctl_kernel+0x1eb/0x3f0 drivers/gpu/drm/drm_ioctl.c:744
 drm_ioctl+0x582/0xb70 drivers/gpu/drm/drm_ioctl.c:841
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x1a1/0x210 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd5/0x270 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f1716e8eeed
Code: c3 e8 97 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 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:00007f1717ba5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1716fe3f80 RCX: 00007f1716e8eeed
RDX: 00000000200003c0 RSI: 00000000c01864c6 RDI: 0000000000000003
RBP: 00007f1716f13014 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f1716fe3f80 R15: 00007f1717b85000
 </TASK>


Thank you for taking the time to read this email and we look forward to working with you further.











[-- Attachment #2: poc.c --]
[-- Type: application/octet-stream, Size: 4415 bytes --]

// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.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;
}

static long syz_open_dev(volatile long a0, volatile long a1, volatile long a2)
{
  if (a0 == 0xc || a0 == 0xb) {
    char buf[128];
    sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1,
            (uint8_t)a2);
    return open(buf, O_RDWR, 0);
  } else {
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf) - 1);
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

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");
}

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();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      sleep_ms(10);
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  memcpy((void*)0x20000080, "/dev/dri/card#\000", 15);
  res = -1;
  res = syz_open_dev(/*dev=*/0x20000080, /*id=*/1, /*flags=*/0);
  if (res != -1)
    r[0] = res;
  *(uint64_t*)0x200003c0 = 0x20000040;
  *(uint32_t*)0x20000040 = 0;
  *(uint32_t*)0x200003c8 = 0xf4240;
  *(uint32_t*)0x200003cc = 0;
  syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xc01864c6, /*arg=*/0x200003c0ul);
}
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);
  const char* reason;
  (void)reason;
  loop();
  return 0;
}