/* \internal Checks whether a tar file is valid. A valid tar file does not contains files that start with ./ or contain .. This is intended to prevent malicious packages placing binaries outside of the sandbox directory */ bool check_tar_valid( const QString &tarfile ) { TAR *tarHandle = get_tar_ptr( tarfile ); bool ret=true; QString filename; int i; while ( (i = th_read(tarHandle)) == 0) { filename = th_get_pathname( tarHandle ); if ( !filename.startsWith("./") || filename.contains( "..") ) { ret = false; qWarning() << "check_tar_valid:- tar contains invalid file path: " << filename << "\nAll paths must begin with ./ and not contain .." ; break; } else if ( TH_ISBLK(tarHandle) || TH_ISCHR(tarHandle) ) { ret = false; qWarning() << "check_tar_valid:-tar invalid, contains device special file:" << filename; break; } else if ( TH_ISLNK(tarHandle) ) { ret = false; qWarning() << "check_tar_valid:-tar invalid, contains hard link:" << filename; break; } else if (TH_ISSYM(tarHandle) ) { QString target; if ((tarHandle->options & TAR_GNU) && tarHandle->th_buf.gnu_longlink != NULL) target = tarHandle->th_buf.gnu_longlink; else target = tarHandle->th_buf.linkname; if ( target.startsWith("/") || target.contains( "..") ) { ret = false; qWarning() << "check_tar_valid:tar invalid, contains symlink whose target" << (target.startsWith("/")?"is an absolute path.":"references " "a parent directory.") << "Link:" << filename << "Target:" << target; break; } } if( TH_ISREG(tarHandle) ) tar_skip_regfile(tarHandle); } tar_close( tarHandle ); return ret; }
/* hardlink */ int tar_extract_hardlink(TAR * t, char *realname, char *prefix) { char *filename; char *linktgt = NULL; char *lnp; libtar_hashptr_t hp; if (!TH_ISLNK(t)) { errno = EINVAL; return -1; } filename = (realname ? realname : th_get_pathname(t)); if (mkdirhier(dirname(filename)) == -1) return -1; libtar_hashptr_reset(&hp); if (libtar_hash_getkey(t->h, &hp, th_get_linkname(t), (libtar_matchfunc_t)libtar_str_match) != 0) { lnp = (char *)libtar_hashptr_data(&hp); linktgt = &lnp[strlen(lnp) + 1]; } else linktgt = th_get_linkname(t); char *newtgt = strdup(linktgt); sprintf(linktgt, "%s/%s", prefix, newtgt); #ifdef DEBUG printf(" ==> extracting: %s (link to %s)\n", filename, linktgt); #endif if (link(linktgt, filename) == -1) { #ifdef DEBUG perror("link()"); #endif printf("Failed restore of hardlink '%s' but returning as if nothing bad happened anyway\n", filename); return 0; // Used to be -1 } return 0; }
/* hardlink */ int tar_extract_hardlink(TAR * t, char *realname) { char *filename; char *linktgt = NULL; char *lnp; libtar_hashptr_t hp; if (!TH_ISLNK(t)) { errno = EINVAL; return -1; } filename = (realname ? realname : th_get_pathname(t)); if (mkdirhier(dirname(filename)) == -1) return -1; libtar_hashptr_reset(&hp); if (libtar_hash_getkey(t->h, &hp, th_get_linkname(t), (libtar_matchfunc_t)libtar_str_match) != 0) { lnp = (char *)libtar_hashptr_data(&hp); linktgt = &lnp[strlen(lnp) + 1]; } else linktgt = th_get_linkname(t); #ifdef DEBUG printf(" ==> extracting: %s (link to %s)\n", filename, linktgt); #endif if (link(linktgt, filename) == -1) { #ifdef DEBUG perror("link()"); #endif return -1; } return 0; }
void th_print_long_ls(TAR *t) { char modestring[12]; struct passwd *pw; struct group *gr; uid_t uid; gid_t gid; char username[_POSIX_LOGIN_NAME_MAX]; char groupname[_POSIX_LOGIN_NAME_MAX]; time_t mtime; struct tm *mtm; #ifdef HAVE_STRFTIME char timebuf[18]; #else const char *months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; #endif uid = th_get_uid(t); pw = getpwuid(uid); if (pw == NULL) snprintf(username, sizeof(username), "%d", uid); else strlcpy(username, pw->pw_name, sizeof(username)); gid = th_get_gid(t); gr = getgrgid(gid); if (gr == NULL) snprintf(groupname, sizeof(groupname), "%d", gid); else strlcpy(groupname, gr->gr_name, sizeof(groupname)); strmode(th_get_mode(t), modestring); printf("%.10s %-8.8s %-8.8s ", modestring, username, groupname); if (TH_ISCHR(t) || TH_ISBLK(t)) printf(" %3d, %3d ", th_get_devmajor(t), th_get_devminor(t)); else printf("%9ld ", (long)th_get_size(t)); mtime = th_get_mtime(t); mtm = localtime(&mtime); #ifdef HAVE_STRFTIME strftime(timebuf, sizeof(timebuf), "%h %e %H:%M %Y", mtm); printf("%s", timebuf); #else printf("%.3s %2d %2d:%02d %4d", months[mtm->tm_mon], mtm->tm_mday, mtm->tm_hour, mtm->tm_min, mtm->tm_year + 1900); #endif printf(" %s", th_get_pathname(t)); if (TH_ISSYM(t) || TH_ISLNK(t)) { if (TH_ISSYM(t)) printf(" -> "); else printf(" link to "); if ((t->options & TAR_GNU) && t->th_buf.gnu_longlink != NULL) printf("%s", t->th_buf.gnu_longlink); else printf("%.100s", t->th_buf.linkname); } putchar('\n'); }
static int tar_set_file_perms(TAR *t, char *realname) { mode_t mode; uid_t uid; gid_t gid; struct utimbuf ut; char *filename; filename = (realname ? realname : th_get_pathname(t)); mode = th_get_mode(t); uid = th_get_uid(t); gid = th_get_gid(t); ut.modtime = ut.actime = th_get_mtime(t); /* change owner/group */ if (geteuid() == 0) #ifdef HAVE_LCHOWN if (lchown(filename, uid, gid) == -1) { # ifdef DEBUG fprintf(stderr, "lchown(\"%s\", %d, %d): %s\n", filename, uid, gid, strerror(errno)); # endif #else /* ! HAVE_LCHOWN */ if (!TH_ISSYM(t) && chown(filename, uid, gid) == -1) { # ifdef DEBUG fprintf(stderr, "chown(\"%s\", %d, %d): %s\n", filename, uid, gid, strerror(errno)); # endif #endif /* HAVE_LCHOWN */ return -1; } /* change access/modification time */ if (!TH_ISSYM(t) && utime(filename, &ut) == -1) { #ifdef DEBUG perror("utime()"); #endif return -1; } /* change permissions */ if (!TH_ISSYM(t) && chmod(filename, mode) == -1) { #ifdef DEBUG perror("chmod()"); #endif return -1; } return 0; } /* switchboard */ int tar_extract_file(TAR *t, char *realname) { int i; char *lnp; int pathname_len; int realname_len; if (t->options & TAR_NOOVERWRITE) { struct stat s; if (lstat(realname, &s) == 0 || errno != ENOENT) { errno = EEXIST; return -1; } } if (TH_ISDIR(t)) { i = tar_extract_dir(t, realname); if (i == 1) i = 0; } else if (TH_ISLNK(t)) i = tar_extract_hardlink(t, realname); else if (TH_ISSYM(t)) i = tar_extract_symlink(t, realname); else if (TH_ISCHR(t)) i = tar_extract_chardev(t, realname); else if (TH_ISBLK(t)) i = tar_extract_blockdev(t, realname); else if (TH_ISFIFO(t)) i = tar_extract_fifo(t, realname); else /* if (TH_ISREG(t)) */ i = tar_extract_regfile(t, realname); if (i != 0) return i; i = tar_set_file_perms(t, realname); if (i != 0) return i; pathname_len = strlen(th_get_pathname(t)) + 1; realname_len = strlen(realname) + 1; lnp = (char *)calloc(1, pathname_len + realname_len); if (lnp == NULL) return -1; strcpy(&lnp[0], th_get_pathname(t)); strcpy(&lnp[pathname_len], realname); #ifdef DEBUG printf("tar_extract_file(): calling libtar_hash_add(): key=\"%s\", " "value=\"%s\"\n", th_get_pathname(t), realname); #endif if (libtar_hash_add(t->h, lnp) != 0) return -1; return 0; }
static int tar_set_file_perms(TAR *t, char *realname) { mode_t mode; uid_t uid; gid_t gid; struct utimbuf ut; char *filename; filename = (realname ? realname : th_get_pathname(t)); mode = th_get_mode(t); uid = th_get_uid(t); gid = th_get_gid(t); ut.modtime = ut.actime = th_get_mtime(t); #ifdef DEBUG printf(" ==> setting perms: %s (mode %04o, uid %d, gid %d)\n", filename, mode, uid, gid); #endif /* change owner/group */ if (geteuid() == 0) #ifdef HAVE_LCHOWN if (lchown(filename, uid, gid) == -1) { # ifdef DEBUG fprintf(stderr, "lchown(\"%s\", %d, %d): %s\n", filename, uid, gid, strerror(errno)); # endif #else /* ! HAVE_LCHOWN */ if (!TH_ISSYM(t) && chown(filename, uid, gid) == -1) { # ifdef DEBUG fprintf(stderr, "chown(\"%s\", %d, %d): %s\n", filename, uid, gid, strerror(errno)); # endif #endif /* HAVE_LCHOWN */ return -1; } /* change access/modification time */ if (!TH_ISSYM(t) && utime(filename, &ut) == -1) { #ifdef DEBUG perror("utime()"); #endif return -1; } /* change permissions */ if (!TH_ISSYM(t) && chmod(filename, mode) == -1) { #ifdef DEBUG perror("chmod()"); #endif return -1; } return 0; } /* switchboard */ int tar_extract_file(TAR *t, char *realname, char *prefix, const int *progress_fd) { int i; char *lnp; int pathname_len; int realname_len; if (t->options & TAR_NOOVERWRITE) { struct stat s; if (lstat(realname, &s) == 0 || errno != ENOENT) { errno = EEXIST; return -1; } } if (TH_ISDIR(t)) { printf("dir\n"); i = tar_extract_dir(t, realname); if (i == 1) i = 0; } else if (TH_ISLNK(t)) { printf("link\n"); i = tar_extract_hardlink(t, realname, prefix); } else if (TH_ISSYM(t)) { printf("sym\n"); i = tar_extract_symlink(t, realname); } else if (TH_ISCHR(t)) { printf("chr\n"); i = tar_extract_chardev(t, realname); } else if (TH_ISBLK(t)) { printf("blk\n"); i = tar_extract_blockdev(t, realname); } else if (TH_ISFIFO(t)) { printf("fifo\n"); i = tar_extract_fifo(t, realname); } else /* if (TH_ISREG(t)) */ { printf("reg\n"); i = tar_extract_regfile(t, realname, progress_fd); } if (i != 0) { printf("FAILED RESTORE OF FILE i: %s\n", realname); return i; } i = tar_set_file_perms(t, realname); if (i != 0) { printf("FAILED SETTING PERMS: %d\n", i); return i; } #ifdef HAVE_SELINUX if((t->options & TAR_STORE_SELINUX) && t->th_buf.selinux_context != NULL) { #ifdef DEBUG printf(" Restoring SELinux context %s to file %s\n", t->th_buf.selinux_context, realname); #endif if (lsetfilecon(realname, t->th_buf.selinux_context) < 0) { fprintf(stderr, "Failed to restore SELinux context %s!\n", strerror(errno)); } } #endif /* pathname_len = strlen(th_get_pathname(t)) + 1; realname_len = strlen(realname) + 1; lnp = (char *)calloc(1, pathname_len + realname_len); if (lnp == NULL) return -1; strcpy(&lnp[0], th_get_pathname(t)); strcpy(&lnp[pathname_len], realname); #ifdef DEBUG printf("tar_extract_file(): calling libtar_hash_add(): key=\"%s\", " "value=\"%s\"\n", th_get_pathname(t), realname); #endif if (libtar_hash_add(t->h, lnp) != 0) return -1; free(lnp); */ return 0; }