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b9ad75fa6

Denis Vlasenko
Denis Vlasenko
2008-03-28
FAILED Duration: 22s

Subject

copy_file: handle "cp /dev/foo file" (almost) compatibly to coreutils. (almost because we do not copy mode, which is probably wasn't intended). +61 bytes.

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

coreutils/mv.c +5 -1include/libbb.h +19 -15libbb/copy_file.c +29 -8testsuite/cp/cp-a-files-to-dir +2 -1testsuite/cp/cp-dev-file +2 -0testsuite/cp/cp-does-not-copy-unreadable-file +6 -1
coreutils/mv.c+5 -1
@@ -71,7 +71,8 @@ int mv_main(int argc, char **argv)
}
DO_MOVE:
- if (dest_exists && !(flags & OPT_FILEUTILS_FORCE)
+ if (dest_exists
+ && !(flags & OPT_FILEUTILS_FORCE)
&& ((access(dest, W_OK) < 0 && isatty(0))
|| (flags & OPT_FILEUTILS_INTERACTIVE))
) {
@@ -108,6 +109,9 @@ int mv_main(int argc, char **argv)
goto RET_1;
}
}
+ /* FILEUTILS_RECUR also prevents nasties like
+ * "read from device and write contents to dst"
+ * instead of "create same device node" */
copy_flag = FILEUTILS_RECUR | FILEUTILS_PRESERVE_STATUS;
#if ENABLE_SELINUX
copy_flag |= FILEUTILS_PRESERVE_SECURITY_CONTEXT;
include/libbb.h+19 -15
@@ -223,8 +223,27 @@ extern char *skip_non_whitespace(const char *);
//TODO: supply a pointer to char[11] buffer (avoid statics)?
extern const char *bb_mode_string(mode_t mode);
extern int is_directory(const char *name, int followLinks, struct stat *statBuf);
+enum { /* DO NOT CHANGE THESE VALUES! cp.c, mv.c, install.c depend on them. */
+ FILEUTILS_PRESERVE_STATUS = 1,
+ FILEUTILS_DEREFERENCE = 2,
+ FILEUTILS_RECUR = 4,
+ FILEUTILS_FORCE = 8,
+ FILEUTILS_INTERACTIVE = 0x10,
+ FILEUTILS_MAKE_HARDLINK = 0x20,
+ FILEUTILS_MAKE_SOFTLINK = 0x40,
+#if ENABLE_SELINUX
+ FILEUTILS_PRESERVE_SECURITY_CONTEXT = 0x80,
+ FILEUTILS_SET_SECURITY_CONTEXT = 0x100
+#endif
+};
+#define FILEUTILS_CP_OPTSTR "pdRfils" USE_SELINUX("c")
extern int remove_file(const char *path, int flags);
+/* NB: without FILEUTILS_RECUR in flags, it will basically "cat"
+ * the source, not copy (unless "source" is a directory).
+ * This makes "cp /dev/null file" and "install /dev/null file" (!!!)
+ * work coreutils-compatibly. */
extern int copy_file(const char *source, const char *dest, int flags);
+
enum {
ACTION_RECURSE = (1 << 0),
ACTION_FOLLOWLINKS = (1 << 1),
@@ -1170,21 +1189,6 @@ void *md5_end(void *resbuf, md5_ctx_t *ctx);
uint32_t *crc32_filltable(uint32_t *tbl256, int endian);
-enum { /* DO NOT CHANGE THESE VALUES! cp.c, mv.c, install.c depend on them. */
- FILEUTILS_PRESERVE_STATUS = 1,
- FILEUTILS_DEREFERENCE = 2,
- FILEUTILS_RECUR = 4,
- FILEUTILS_FORCE = 8,
- FILEUTILS_INTERACTIVE = 0x10,
- FILEUTILS_MAKE_HARDLINK = 0x20,
- FILEUTILS_MAKE_SOFTLINK = 0x40,
-#if ENABLE_SELINUX
- FILEUTILS_PRESERVE_SECURITY_CONTEXT = 0x80,
- FILEUTILS_SET_SECURITY_CONTEXT = 0x100
-#endif
-};
-
-#define FILEUTILS_CP_OPTSTR "pdRfils" USE_SELINUX("c")
extern const char *applet_name;
/* "BusyBox vN.N.N (timestamp or extra_version)" */
extern const char bb_banner[];
libbb/copy_file.c+29 -8
@@ -81,6 +81,7 @@ int copy_file(const char *source, const char *dest, int flags)
signed char dest_exists = 0;
signed char ovr;
+/* Inverse of cp -d ("cp without -d") */
#define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE)
if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) {
@@ -229,12 +230,22 @@ int copy_file(const char *source, const char *dest, int flags)
return 0;
}
- if (S_ISREG(source_stat.st_mode)
- /* DEREF uses stat, which never returns S_ISLNK() == true. */
+ if (/* "cp thing1 thing2" without -R: just open and read() from thing1 */
+ !(flags & FILEUTILS_RECUR)
+ /* "cp [-opts] regular_file thing2" */
+ || S_ISREG(source_stat.st_mode)
+ /* DEREF uses stat, which never returns S_ISLNK() == true.
+ * So the below is never true: */
/* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */
) {
int src_fd;
int dst_fd;
+ mode_t new_mode;
+
+ if (!FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) {
+ /* "cp -d symlink dst": create a link */
+ goto dont_cat;
+ }
if (ENABLE_FEATURE_PRESERVE_HARDLINKS && !FLAGS_DEREF) {
const char *link_target;
@@ -258,18 +269,24 @@ int copy_file(const char *source, const char *dest, int flags)
if (src_fd < 0)
return -1;
+ /* Do not try to open with weird mode fields */
+ new_mode = source_stat.st_mode;
+ if (!S_ISREG(source_stat.st_mode))
+ new_mode = 0666;
+
/* POSIX way is a security problem versus symlink attacks,
* we do it only for non-symlinks, and only for non-recursive,
* non-interactive cp. NB: it is still racy
* for "cp file /home/bad_user/file" case
* (user can rm file and create a link to /etc/passwd) */
if (DO_POSIX_CP
- || (dest_exists && !(flags & (FILEUTILS_RECUR|FILEUTILS_INTERACTIVE))
+ || (dest_exists
+ && !(flags & (FILEUTILS_RECUR|FILEUTILS_INTERACTIVE))
&& !S_ISLNK(dest_stat.st_mode))
) {
- dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode);
+ dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, new_mode);
} else /* safe way: */
- dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, source_stat.st_mode);
+ dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode);
if (dst_fd == -1) {
ovr = ask_and_unlink(dest, flags);
if (ovr <= 0) {
@@ -277,7 +294,7 @@ int copy_file(const char *source, const char *dest, int flags)
return ovr;
}
/* It shouldn't exist. If it exists, do not open (symlink attack?) */
- dst_fd = open3_or_warn(dest, O_WRONLY|O_CREAT|O_EXCL, source_stat.st_mode);
+ dst_fd = open3_or_warn(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode);
if (dst_fd < 0) {
close(src_fd);
return -1;
@@ -285,8 +302,7 @@ int copy_file(const char *source, const char *dest, int flags)
}
#if ENABLE_SELINUX
- if (((flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT)
- || (flags & FILEUTILS_SET_SECURITY_CONTEXT))
+ if ((flags & (FILEUTILS_PRESERVE_SECURITY_CONTEXT|FILEUTILS_SET_SECURITY_CONTEXT))
&& is_selinux_enabled() > 0
) {
security_context_t con;
@@ -313,8 +329,13 @@ int copy_file(const char *source, const char *dest, int flags)
}
/* ...but read size is already checked by bb_copyfd_eof */
close(src_fd);
+ /* "cp /dev/something new_file" should not
+ * copy mode of /dev/something */
+ if (!S_ISREG(source_stat.st_mode))
+ return retval;
goto preserve_mode_ugid_time;
}
+ dont_cat:
/* Source is a symlink or a special file */
/* We are lazy here, a bit lax with races... */
testsuite/cp/cp-a-files-to-dir+2 -1
@@ -2,7 +2,8 @@ echo file number one > file1
echo file number two > file2
ln -s file2 link1
mkdir dir1
-touch --date='Sat Jan 29 21:24:08 PST 2000' dir1/file3
+# why???
+#touch --date='Sat Jan 29 21:24:08 PST 2000' dir1/file3
mkdir there
busybox cp -a file1 file2 link1 dir1 there
test -f there/file1
testsuite/cp/cp-dev-file+2 -0
@@ -0,0 +1,2 @@
+busybox cp /dev/null foo
+test -f foo
testsuite/cp/cp-does-not-copy-unreadable-file+6 -1
@@ -1,6 +1,11 @@
touch foo
chmod a-r foo
set +e
-busybox cp foo bar
+if test `id -u` = 0; then
+ # run as user with nonzero uid
+ setuidgid 1 busybox cp foo bar
+else
+ busybox cp foo bar
+fi
set -e
test ! -f bar