libsandbox: handle ENAMETOOLONG properly with getcwd()

The core libsandbox code was checking for ENAMETOOLONG when working with
getcwd() and doing the right thing, but it never passed this error back up
to the caller.  This would make some tests (like the getcwd tests in many
gnulib/autotool based packages like coreutils) to keep on trying since it
did not detect the expected failure conditions.  So now when we hit the
ENAMETOOLONG error, we pass this specific error back up to the caller.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 11 insertions, 14 deletions

diff --git a/libsandbox/libsandbox.c b/libsandbox/libsandbox.c
index 51fe059..930724d 100644
--- a/libsandbox/libsandbox.c
+++ b/libsandbox/libsandbox.c
@@ -66,7 +66,6 @@ static sbcontext_t sbcontext;
 static char **cached_env_vars;
 volatile int sandbox_on = 1;
 static int sb_init = 0;
-static int sb_path_size_warning = 0;
 
 static char *resolve_path(const char *, int);
 static int write_logfile(const char *, const char *, const char *,
@@ -715,6 +714,11 @@ out:
 	return result;
 }
 
+/* Return values:
+ *  0: failure, caller should abort
+ *  1: things worked out fine
+ *  2: things worked out fine, but the errno should not be restored
+ */
 static int check_syscall(sbcontext_t *sbcontext, int sb_nr, const char *func, const char *file)
 {
 	char *absolute_path = NULL;
@@ -791,16 +795,10 @@ error:
 		free(resolved_path);
 
 	/* The path is too long to be canonicalized, so just warn and let the
-	 * function handle it (see bug #94630 and #21766 for more info) */
-	if (ENAMETOOLONG == errno) {
-		if (0 == sb_path_size_warning) {
-			SB_EWARN("PATH LENGTH", "  %s:%*s%s\n",
-			      func, (int)(10 - strlen(func)), "", file);
-			sb_path_size_warning = 1;
-		}
-
-		return 1;
-	}
+	 * function handle it (see bugs #21766 #94630 #101728 #227947)
+	 */
+	if (ENAMETOOLONG == errno)
+		return 2;
 
 	/* If we get here, something bad happened */
 	SB_EERROR("ISE ", "Unrecoverable error: %s\n", strerror(errno));
@@ -900,8 +898,6 @@ int before_syscall(int dirfd, int sb_nr, const char *func, const char *file)
 	if (at_file_buf)
 		free(at_file_buf);
 
-	errno = old_errno;
-
 	if (0 == result) {
 		if ((NULL != getenv(ENV_SANDBOX_PID)) && (is_env_on(ENV_SANDBOX_ABORT)))
 			kill(atoi(getenv(ENV_SANDBOX_PID)), SIGUSR1);
@@ -910,7 +906,8 @@ int before_syscall(int dirfd, int sb_nr, const char *func, const char *file)
 		 *        error to be returned (EINVAL for invalid mode for
 		 *        fopen() and co, ETOOLONG, etc). */
 		errno = EACCES;
-	}
+	} else if (result == 1)
+		errno = old_errno;
 
 	return result;
 }