upstream: Sanitize scp filenames via snmprintf. To do this we move

the progressmeter formatting outside of signal handler context and have the
atomicio callback called for EINTR too.  bz#2434 with contributions from djm
and jjelen at redhat.com, ok djm@

OpenBSD-Commit-ID: 1af61c1f70e4f3bd8ab140b9f1fa699481db57d8

CVE-2019-6109

Origin: backport, https://anongit.mindrot.org/openssh.git/commit/?id=8976f1c4b2721c26e878151f52bdf346dfe2d54c
Bug-Debian: https://bugs.debian.org/793412
Last-Update: 2019-02-08

Patch-Name: sanitize-scp-filenames-via-snmprintf.patch

1 files changed, 24 insertions, 29 deletions

diff --git a/progressmeter.c b/progressmeter.c
index fe9bf52e4..add462dde 100644
--- a/progressmeter.c
+++ b/progressmeter.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: progressmeter.c,v 1.45 2016/06/30 05:17:05 dtucker Exp $ */
+/* $OpenBSD: progressmeter.c,v 1.46 2019/01/23 08:01:46 dtucker Exp $ */
 /*
  * Copyright (c) 2003 Nils Nordman.  All rights reserved.
  *
@@ -31,6 +31,7 @@
 
 #include <errno.h>
 #include <signal.h>
+#include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
@@ -39,6 +40,7 @@
 #include "progressmeter.h"
 #include "atomicio.h"
 #include "misc.h"
+#include "utf8.h"
 
 #define DEFAULT_WINSIZE 80
 #define MAX_WINSIZE 512
@@ -61,7 +63,7 @@ static void setscreensize(void);
 void refresh_progress_meter(void);
 
 /* signal handler for updating the progress meter */
-static void update_progress_meter(int);
+static void sig_alarm(int);
 
 static double start;            /* start progress */
 static double last_update;      /* last progress update */
@@ -74,6 +76,7 @@ static long stalled;		/* how long we have been stalled */
 static int bytes_per_second;    /* current speed in bytes per second */
 static int win_size;            /* terminal window size */
 static volatile sig_atomic_t win_resized; /* for window resizing */
+static volatile sig_atomic_t alarm_fired;
 
 /* units for format_size */
 static const char unit[] = " KMGT";
@@ -126,9 +129,17 @@ refresh_progress_meter(void)
         off_t bytes_left;
         int cur_speed;
         int hours, minutes, seconds;
-        int i, len;
         int file_len;
 
+        if ((!alarm_fired && !win_resized) || !can_output())
+                return;
+        alarm_fired = 0;
+
+        if (win_resized) {
+                setscreensize();
+                win_resized = 0;
+        }
+
         transferred = *counter - (cur_pos ? cur_pos : start_pos);
         cur_pos = *counter;
         now = monotime_double();
@@ -158,16 +169,11 @@ refresh_progress_meter(void)
 
         /* filename */
         buf[0] = '\0';
-        file_len = win_size - 35;
+        file_len = win_size - 36;
         if (file_len > 0) {
-                len = snprintf(buf, file_len + 1, "\r%s", file);
-                if (len < 0)
-                        len = 0;
-                if (len >= file_len + 1)
-                        len = file_len;
-                for (i = len; i < file_len; i++)
-                        buf[i] = ' ';
-                buf[file_len] = '\0';
+                buf[0] = '\r';
+                snmprintf(buf+1, sizeof(buf)-1 , &file_len, "%*s",
+                    file_len * -1, file);
         }
 
         /* percent of transfer done */
@@ -228,22 +234,11 @@ refresh_progress_meter(void)
 
 /*ARGSUSED*/
 static void
-update_progress_meter(int ignore)
+sig_alarm(int ignore)
 {
-        int save_errno;
-
-        save_errno = errno;
-
-        if (win_resized) {
-                setscreensize();
-                win_resized = 0;
-        }
-        if (can_output())
-                refresh_progress_meter();
-
-        signal(SIGALRM, update_progress_meter);
+        signal(SIGALRM, sig_alarm);
+        alarm_fired = 1;
         alarm(UPDATE_INTERVAL);
-        errno = save_errno;
 }
 
 void
@@ -259,10 +254,9 @@ start_progress_meter(const char *f, off_t filesize, off_t *ctr)
         bytes_per_second = 0;
 
         setscreensize();
-        if (can_output())
-                refresh_progress_meter();
+        refresh_progress_meter();
 
-        signal(SIGALRM, update_progress_meter);
+        signal(SIGALRM, sig_alarm);
         signal(SIGWINCH, sig_winch);
         alarm(UPDATE_INTERVAL);
 }
@@ -286,6 +280,7 @@ stop_progress_meter(void)
 static void
 sig_winch(int sig)
 {
+        signal(SIGWINCH, sig_winch);
         win_resized = 1;
 }