kumquat-buildroot/package/openssh/0002-upstream-Sanitize-scp-filenames-via-snmprintf.-To-do.patch
Baruch Siach 7fe3741bc4 openssh: add upstream security fixes
CVE-2019-6109: Due to missing character encoding in the progress
display, a malicious server (or Man-in-The-Middle attacker) can employ
crafted object names to manipulate the client output, e.g., by using
ANSI control codes to hide additional files being transferred. This
affects refresh_progress_meter() in progressmeter.c.

CVE-2019-6111: Due to the scp implementation being derived from 1983
rcp, the server chooses which files/directories are sent to the client.
However, the scp client only performs cursory validation of the object
name returned (only directory traversal attacks are prevented). A
malicious scp server (or Man-in-The-Middle attacker) can overwrite
arbitrary files in the scp client target directory. If recursive
operation (-r) is performed, the server can manipulate subdirectories as
well (for example, to overwrite the .ssh/authorized_keys file).

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2019-02-12 19:59:11 +01:00

276 lines
8.0 KiB
Diff

From 5979bdfeca813dd7e997a1edb0f928d77ce70304 Mon Sep 17 00:00:00 2001
From: "dtucker@openbsd.org" <dtucker@openbsd.org>
Date: Wed, 23 Jan 2019 08:01:46 +0000
Subject: [PATCH] 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
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
Upstream status (openssh-portable): backported from commit 8976f1c4b27
---
atomicio.c | 20 ++++++++++++++-----
progressmeter.c | 53 ++++++++++++++++++++++---------------------------
progressmeter.h | 3 ++-
scp.c | 1 +
sftp-client.c | 16 ++++++++-------
5 files changed, 51 insertions(+), 42 deletions(-)
diff --git a/atomicio.c b/atomicio.c
index f854a06f5f50..d91bd7621c12 100644
--- a/atomicio.c
+++ b/atomicio.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: atomicio.c,v 1.28 2016/07/27 23:18:12 djm Exp $ */
+/* $OpenBSD: atomicio.c,v 1.29 2019/01/23 08:01:46 dtucker Exp $ */
/*
* Copyright (c) 2006 Damien Miller. All rights reserved.
* Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
@@ -65,9 +65,14 @@ atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
res = (f) (fd, s + pos, n - pos);
switch (res) {
case -1:
- if (errno == EINTR)
+ if (errno == EINTR) {
+ /* possible SIGALARM, update callback */
+ if (cb != NULL && cb(cb_arg, 0) == -1) {
+ errno = EINTR;
+ return pos;
+ }
continue;
- if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
#ifndef BROKEN_READ_COMPARISON
(void)poll(&pfd, 1, -1);
#endif
@@ -122,9 +127,14 @@ atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
res = (f) (fd, iov, iovcnt);
switch (res) {
case -1:
- if (errno == EINTR)
+ if (errno == EINTR) {
+ /* possible SIGALARM, update callback */
+ if (cb != NULL && cb(cb_arg, 0) == -1) {
+ errno = EINTR;
+ return pos;
+ }
continue;
- if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
#ifndef BROKEN_READV_COMPARISON
(void)poll(&pfd, 1, -1);
#endif
diff --git a/progressmeter.c b/progressmeter.c
index fe9bf52e4c90..add462dde500 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;
}
diff --git a/progressmeter.h b/progressmeter.h
index bf179dca6518..8f6678060195 100644
--- a/progressmeter.h
+++ b/progressmeter.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: progressmeter.h,v 1.3 2015/01/14 13:54:13 djm Exp $ */
+/* $OpenBSD: progressmeter.h,v 1.4 2019/01/23 08:01:46 dtucker Exp $ */
/*
* Copyright (c) 2002 Nils Nordman. All rights reserved.
*
@@ -24,4 +24,5 @@
*/
void start_progress_meter(const char *, off_t, off_t *);
+void refresh_progress_meter(void);
void stop_progress_meter(void);
diff --git a/scp.c b/scp.c
index 4f3fdcd3db89..4a342a63873c 100644
--- a/scp.c
+++ b/scp.c
@@ -585,6 +585,7 @@ scpio(void *_cnt, size_t s)
off_t *cnt = (off_t *)_cnt;
*cnt += s;
+ refresh_progress_meter();
if (limit_kbps > 0)
bandwidth_limit(&bwlimit, s);
return 0;
diff --git a/sftp-client.c b/sftp-client.c
index 4986d6d8d291..2bc698f868bc 100644
--- a/sftp-client.c
+++ b/sftp-client.c
@@ -101,7 +101,9 @@ sftpio(void *_bwlimit, size_t amount)
{
struct bwlimit *bwlimit = (struct bwlimit *)_bwlimit;
- bandwidth_limit(bwlimit, amount);
+ refresh_progress_meter();
+ if (bwlimit != NULL)
+ bandwidth_limit(bwlimit, amount);
return 0;
}
@@ -121,8 +123,8 @@ send_msg(struct sftp_conn *conn, struct sshbuf *m)
iov[1].iov_base = (u_char *)sshbuf_ptr(m);
iov[1].iov_len = sshbuf_len(m);
- if (atomiciov6(writev, conn->fd_out, iov, 2,
- conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_out) !=
+ if (atomiciov6(writev, conn->fd_out, iov, 2, sftpio,
+ conn->limit_kbps > 0 ? &conn->bwlimit_out : NULL) !=
sshbuf_len(m) + sizeof(mlen))
fatal("Couldn't send packet: %s", strerror(errno));
@@ -138,8 +140,8 @@ get_msg_extended(struct sftp_conn *conn, struct sshbuf *m, int initial)
if ((r = sshbuf_reserve(m, 4, &p)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
- if (atomicio6(read, conn->fd_in, p, 4,
- conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_in) != 4) {
+ if (atomicio6(read, conn->fd_in, p, 4, sftpio,
+ conn->limit_kbps > 0 ? &conn->bwlimit_in : NULL) != 4) {
if (errno == EPIPE || errno == ECONNRESET)
fatal("Connection closed");
else
@@ -157,8 +159,8 @@ get_msg_extended(struct sftp_conn *conn, struct sshbuf *m, int initial)
if ((r = sshbuf_reserve(m, msg_len, &p)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
- if (atomicio6(read, conn->fd_in, p, msg_len,
- conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_in)
+ if (atomicio6(read, conn->fd_in, p, msg_len, sftpio,
+ conn->limit_kbps > 0 ? &conn->bwlimit_in : NULL)
!= msg_len) {
if (errno == EPIPE)
fatal("Connection closed");
--
2.20.1