← Commit list

9acd63c92

Denys Vlasenko

2018-03-28

SUCCESS Duration: 140s

Subject

ash,hush: fix "saved" redirected fds still visible in children

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 →

shell/ash.c+11 -5

@@ -255,6 +255,9 @@ typedef long arith_t;
	# define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
	#endif

+	#ifndef F_DUPFD_CLOEXEC
+	# define F_DUPFD_CLOEXEC F_DUPFD
+	#endif
	#ifndef PIPE_BUF
	# define PIPE_BUF 4096 /* amount of buffering in a pipe */
	#endif
@@ -5448,12 +5451,15 @@ dup2_or_raise(int from, int to)
	return newfd;
	}
	static int
-	fcntl_F_DUPFD(int fd, int avoid_fd)
+	dup_CLOEXEC(int fd, int avoid_fd)
	{
	int newfd;
	repeat:
-	newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
-	if (newfd < 0) {
+	newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
+	if (newfd >= 0) {
+	if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
+	fcntl(newfd, F_SETFD, FD_CLOEXEC);
+	} else { /* newfd < 0 */
	if (errno == EBUSY)
	goto repeat;
	if (errno == EINTR)
@@ -5569,7 +5575,7 @@ save_fd_on_redirect(int fd, int avoid_fd, struct redirtab *sq)
	for (i = 0; sq->two_fd[i].orig_fd != EMPTY; i++) {
	/* If we collide with an already moved fd... */
	if (fd == sq->two_fd[i].moved_to) {
-	new_fd = fcntl_F_DUPFD(fd, avoid_fd);
+	new_fd = dup_CLOEXEC(fd, avoid_fd);
	sq->two_fd[i].moved_to = new_fd;
	TRACE(("redirect_fd %d: already busy, moving to %d\n", fd, new_fd));
	if (new_fd < 0) /* what? */
@@ -5584,7 +5590,7 @@ save_fd_on_redirect(int fd, int avoid_fd, struct redirtab *sq)
	}

	/* If this fd is open, we move and remember it; if it's closed, new_fd = CLOSED (-1) */
-	new_fd = fcntl_F_DUPFD(fd, avoid_fd);
+	new_fd = dup_CLOEXEC(fd, avoid_fd);
	TRACE(("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, new_fd));
	if (new_fd < 0) {
	if (errno != EBADF)

shell/ash_test/ash-redir/redir_children_should_not_see_saved_fd_1.right+5 -0

@@ -0,0 +1,5 @@
+	/proc/self/fd
+	/proc/self/fd/0
+	/proc/self/fd/1
+	/proc/self/fd/2
+	/proc/self/fd/3

shell/ash_test/ash-redir/redir_children_should_not_see_saved_fd_1.tests+6 -0

@@ -0,0 +1,6 @@
+	# The "find" should not see "saved" (duplicated) fd #1
+	# Explicitly use bbox find, since other implementations of "find"
+	# may open other descriptors as well.
+	busybox find /proc/self/fd >tmp_$$.out
+	cat tmp_$$.out
+	rm -f tmp_$$.out

shell/ash_test/ash-redir/redir_children_should_not_see_saved_fd_2.right+5 -0

@@ -0,0 +1,5 @@
+	/proc/self/fd
+	/proc/self/fd/0
+	/proc/self/fd/1
+	/proc/self/fd/2
+	/proc/self/fd/3

shell/ash_test/ash-redir/redir_children_should_not_see_saved_fd_2.tests+6 -0

@@ -0,0 +1,6 @@
+	# The "find" should not see "saved" (duplicated) fd #1
+	# Explicitly use bbox find, since other implementations of "find"
+	# may open other descriptors as well.
+	{ busybox find /proc/self/fd; } >tmp_$$.out
+	cat tmp_$$.out
+	rm -f tmp_$$.out

shell/ash_test/ash-redir/redir_children_should_not_see_saved_fd_3.right+5 -0

@@ -0,0 +1,5 @@
+	/proc/self/fd
+	/proc/self/fd/0
+	/proc/self/fd/1
+	/proc/self/fd/2
+	/proc/self/fd/3

shell/ash_test/ash-redir/redir_children_should_not_see_saved_fd_3.tests+6 -0

@@ -0,0 +1,6 @@
+	# The "find" should not see "saved" (duplicated) fd #1
+	# Explicitly use bbox find, since other implementations of "find"
+	# may open other descriptors as well.
+	{ busybox find /proc/self/fd; true; } >tmp_$$.out
+	cat tmp_$$.out
+	rm -f tmp_$$.out

shell/hush.c+15 -8

@@ -1501,12 +1501,15 @@ static void free_strings(char **strings)
	free(strings);
	}

-	static int fcntl_F_DUPFD(int fd, int avoid_fd)
+	static int dup_CLOEXEC(int fd, int avoid_fd)
	{
	int newfd;
	repeat:
-	newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
-	if (newfd < 0) {
+	newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
+	if (newfd >= 0) {
+	if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
+	fcntl(newfd, F_SETFD, FD_CLOEXEC);
+	} else { /* newfd < 0 */
	if (errno == EBUSY)
	goto repeat;
	if (errno == EINTR)
@@ -6890,7 +6893,7 @@ static struct squirrel add_squirrel(struct squirrel sq, int fd, int avoid_fd)
	if (sq) for (; sq[i].orig_fd >= 0; i++) {
	/* If we collide with an already moved fd... */
	if (fd == sq[i].moved_to) {
-	sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
+	sq[i].moved_to = dup_CLOEXEC(sq[i].moved_to, avoid_fd);
	debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
	if (sq[i].moved_to < 0) /* what? */
	xfunc_die();
@@ -6904,7 +6907,7 @@ static struct squirrel add_squirrel(struct squirrel sq, int fd, int avoid_fd)
	}

	/* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
-	moved_to = fcntl_F_DUPFD(fd, avoid_fd);
+	moved_to = dup_CLOEXEC(fd, avoid_fd);
	debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
	if (moved_to < 0 && errno != EBADF)
	xfunc_die();
@@ -7622,6 +7625,10 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
	*/
	close_saved_fds_and_FILE_fds();
	//FIXME: should also close saved redir fds
+	//This casuses test failures in
+	//redir_children_should_not_see_saved_fd_2.tests
+	//redir_children_should_not_see_saved_fd_3.tests
+	//if you replace "busybox find" with just "find" in them
	/* Without this, "rm -i FILE" can't be ^C'ed: */
	switch_off_special_sigs(G.special_sig_mask);
	debug_printf_exec("running applet '%s'\n", argv[0]);
@@ -9347,7 +9354,7 @@ int hush_main(int argc, char **argv)
	G_saved_tty_pgrp = 0;

	/* try to dup stdin to high fd#, >= 255 */
-	G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
+	G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254);
	if (G_interactive_fd < 0) {
	/* try to dup to any fd */
	G_interactive_fd = dup(STDIN_FILENO);
@@ -9420,10 +9427,10 @@ int hush_main(int argc, char **argv)
	#elif ENABLE_HUSH_INTERACTIVE
	/* No job control compiled in, only prompt/line editing */
	if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
-	G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
+	G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254);
	if (G_interactive_fd < 0) {
	/* try to dup to any fd */
-	G_interactive_fd = dup(STDIN_FILENO);
+	G_interactive_fd = dup_CLOEXEC(STDIN_FILENO);
	if (G_interactive_fd < 0)
	/* give up */
	G_interactive_fd = 0;

shell/hush_test/hush-redir/redir_children_should_not_see_saved_fd_1.right+5 -0

@@ -0,0 +1,5 @@
+	/proc/self/fd
+	/proc/self/fd/0
+	/proc/self/fd/1
+	/proc/self/fd/2
+	/proc/self/fd/3

shell/hush_test/hush-redir/redir_children_should_not_see_saved_fd_1.tests+6 -0

@@ -0,0 +1,6 @@
+	# The "find" should not see "saved" (duplicated) fd #1
+	# Explicitly use bbox find, since other implementations of "find"
+	# may open other descriptors as well.
+	busybox find /proc/self/fd >tmp_$$.out
+	cat tmp_$$.out
+	rm -f tmp_$$.out

shell/hush_test/hush-redir/redir_children_should_not_see_saved_fd_2.right+5 -0

@@ -0,0 +1,5 @@
+	/proc/self/fd
+	/proc/self/fd/0
+	/proc/self/fd/1
+	/proc/self/fd/2
+	/proc/self/fd/3

shell/hush_test/hush-redir/redir_children_should_not_see_saved_fd_2.tests+6 -0

@@ -0,0 +1,6 @@
+	# The "find" should not see "saved" (duplicated) fd #1
+	# Explicitly use bbox find, since other implementations of "find"
+	# may open other descriptors as well.
+	{ busybox find /proc/self/fd; } >tmp_$$.out
+	cat tmp_$$.out
+	rm -f tmp_$$.out

shell/hush_test/hush-redir/redir_children_should_not_see_saved_fd_3.right+5 -0

@@ -0,0 +1,5 @@
+	/proc/self/fd
+	/proc/self/fd/0
+	/proc/self/fd/1
+	/proc/self/fd/2
+	/proc/self/fd/3

shell/hush_test/hush-redir/redir_children_should_not_see_saved_fd_3.tests+6 -0

@@ -0,0 +1,6 @@
+	# The "find" should not see "saved" (duplicated) fd #1
+	# Explicitly use bbox find, since other implementations of "find"
+	# may open other descriptors as well.
+	{ busybox find /proc/self/fd; true; } >tmp_$$.out
+	cat tmp_$$.out
+	rm -f tmp_$$.out