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cp: detect and prevent infinite recursion

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This commit is contained in:
Denis Vlasenko 2007-08-27 16:51:30 +00:00
parent 512499c8ca
commit 8a5fab6333
1 changed files with 35 additions and 17 deletions
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52
libbb/copy_file.c
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@ -114,6 +114,7 @@ int copy_file(const char *source, const char *dest, int flags)
if (S_ISDIR(source_stat.st_mode)) {
DIR *dp;
const char *existing_name;
struct dirent *d;
mode_t saved_umask = 0;
@ -122,6 +123,15 @@ int copy_file(const char *source, const char *dest, int flags)
return -1;
}
/* Did we ever create source ourself before? */
existing_name = is_in_ino_dev_hashtable(&source_stat);
if (existing_name) {
/* We did! it's a recursion! man the lifeboats... */
bb_error_msg("recursion detected, omitting directory '%s'",
existing_name);
return -1;
}
/* Create DEST */
if (dest_exists) {
if (!S_ISDIR(dest_stat.st_mode)) {
@ -143,7 +153,15 @@ int copy_file(const char *source, const char *dest, int flags)
return -1;
}
umask(saved_umask);
/* need stat info for add_to_ino_dev_hashtable */
if (lstat(dest, &dest_stat) < 0) {
bb_perror_msg("cannot stat '%s'", dest);
return -1;
}
}
/* remember (dev,inode) of each created dir.
* NULL: name is not remembered */
add_to_ino_dev_hashtable(&dest_stat, NULL);
/* Recursively copy files in SOURCE */
dp = opendir(source);
@ -169,8 +187,8 @@ int copy_file(const char *source, const char *dest, int flags)
if (!dest_exists
&& chmod(dest, source_stat.st_mode & ~saved_umask) < 0
) {
bb_perror_msg("cannot change permissions of '%s'", dest);
retval = -1;
bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
/* retval = -1; - WRONG! copy *WAS* made */
}
goto preserve_mode_ugid_time;
}
@ -197,7 +215,7 @@ int copy_file(const char *source, const char *dest, int flags)
}
if (S_ISREG(source_stat.st_mode)
/* Huh? DEREF uses stat, which never returns links! */
/* DEREF uses stat, which never returns S_ISLNK() == true. */
/* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */
) {
int src_fd;
@ -269,14 +287,13 @@ int copy_file(const char *source, const char *dest, int flags)
#endif
if (bb_copyfd_eof(src_fd, dst_fd) == -1)
retval = -1;
/* Ok, writing side I can understand... */
if (close(dst_fd) < 0) {
bb_perror_msg("cannot close '%s'", dest);
retval = -1;
}
if (close(src_fd) < 0) {
bb_perror_msg("cannot close '%s'", source);
retval = -1;
}
/* ...but read size is already checked by bb_copyfd_eof */
close(src_fd);
goto preserve_mode_ugid_time;
}
@ -289,18 +306,18 @@ int copy_file(const char *source, const char *dest, int flags)
return ovr;
}
if (S_ISLNK(source_stat.st_mode)) {
char *lpath;
lpath = xmalloc_readlink_or_warn(source);
if (lpath && symlink(lpath, dest) < 0) {
bb_perror_msg("cannot create symlink '%s'", dest);
char *lpath = xmalloc_readlink_or_warn(source);
if (lpath) {
int r = symlink(lpath, dest);
free(lpath);
return -1;
if (r < 0) {
bb_perror_msg("cannot create symlink '%s'", dest);
return -1;
}
if (flags & FILEUTILS_PRESERVE_STATUS)
if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
}
free(lpath);
if (flags & FILEUTILS_PRESERVE_STATUS)
if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
/* _Not_ jumping to preserve_mode_ugid_time:
* symlinks don't have those */
return 0;
@ -327,6 +344,7 @@ int copy_file(const char *source, const char *dest, int flags)
times.actime = source_stat.st_atime;
times.modtime = source_stat.st_mtime;
/* BTW, utimes sets usec-precision time - just FYI */
if (utime(dest, &times) < 0)
bb_perror_msg("cannot preserve %s of '%s'", "times", dest);
if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) {