Fix segfault when listen() returns an error

Resolves: rhbz#1666380
This commit is contained in:
Ondřej Lysoněk 2019-08-03 20:07:39 +02:00
parent 2bc5223ce6
commit a0a47ca688
3 changed files with 160 additions and 1 deletions

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@ -0,0 +1,46 @@
From 40fea4552377504ce69935149e64e39a595f4600 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Lyson=C4=9Bk?= <olysonek@redhat.com>
Date: Sat, 3 Aug 2019 17:50:14 +0200
Subject: [PATCH 1/2] Move closing standard FDs after listen()
The vsf_sysutil_close() calls need to be moved a bit further so that
die() works properly in case listen() fails.
I see no reason the calls should be placed before listen()
specifically, as they are now. My guess is that the author who added
the calls thought that listen() is a blocking call, which is not the
case. The only thing we need to satisfy is that close() is called
before accept, because that is a blocking call. That's all that is
needed to fix the bug that was fixed by adding the close() calls.
Resolves: rhbz#1666380
---
standalone.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/standalone.c b/standalone.c
index 3f35e9e..b358ca1 100644
--- a/standalone.c
+++ b/standalone.c
@@ -152,15 +152,15 @@ vsf_standalone_main(void)
vsf_sysutil_kill(vsf_sysutil_getppid(), kVSFSysUtilSigUSR1);
}
}
- vsf_sysutil_close(0);
- vsf_sysutil_close(1);
- vsf_sysutil_close(2);
retval = vsf_sysutil_listen(listen_sock, VSFTP_LISTEN_BACKLOG);
if (vsf_sysutil_retval_is_error(retval))
{
die("could not listen");
}
vsf_sysutil_sockaddr_alloc(&p_accept_addr);
+ vsf_sysutil_close(0);
+ vsf_sysutil_close(1);
+ vsf_sysutil_close(2);
while (1)
{
struct vsf_client_launch child_info;
--
2.20.1

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@ -0,0 +1,107 @@
From e679a3ce0f2cf1558da31e0bccd9e2398b89c7e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Lyson=C4=9Bk?= <olysonek@redhat.com>
Date: Tue, 30 Jul 2019 16:07:01 +0200
Subject: [PATCH 2/2] Prevent recursion in bug()
Resolves: rhbz#1666380
---
sysutil.c | 35 +++++++++++++++++++++++++++++++----
sysutil.h | 1 +
utility.c | 12 +++++++-----
3 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/sysutil.c b/sysutil.c
index fd07d99..e2df671 100644
--- a/sysutil.c
+++ b/sysutil.c
@@ -774,21 +774,48 @@ vsf_sysutil_deactivate_linger_failok(int fd)
(void) setsockopt(fd, SOL_SOCKET, SO_LINGER, &the_linger, sizeof(the_linger));
}
-void
-vsf_sysutil_activate_noblock(int fd)
+static int
+vsf_sysutil_activate_noblock_internal(int fd, int return_err)
{
int retval;
int curr_flags = fcntl(fd, F_GETFL);
if (vsf_sysutil_retval_is_error(curr_flags))
{
- die("fcntl");
+ if (return_err)
+ {
+ return -1;
+ }
+ else
+ {
+ die("fcntl");
+ }
}
curr_flags |= O_NONBLOCK;
retval = fcntl(fd, F_SETFL, curr_flags);
if (retval != 0)
{
- die("fcntl");
+ if (return_err)
+ {
+ return -1;
+ }
+ else
+ {
+ die("fcntl");
+ }
}
+ return 0;
+}
+
+void
+vsf_sysutil_activate_noblock(int fd)
+{
+ (void) vsf_sysutil_activate_noblock_internal(fd, 0);
+}
+
+int
+vsf_sysutil_activate_noblock_no_die(int fd)
+{
+ return vsf_sysutil_activate_noblock_internal(fd, 1);
}
void
diff --git a/sysutil.h b/sysutil.h
index 2df14ed..0772423 100644
--- a/sysutil.h
+++ b/sysutil.h
@@ -281,6 +281,7 @@ void vsf_sysutil_activate_oobinline(int fd);
void vsf_sysutil_activate_linger(int fd);
void vsf_sysutil_deactivate_linger_failok(int fd);
void vsf_sysutil_activate_noblock(int fd);
+int vsf_sysutil_activate_noblock_no_die(int fd);
void vsf_sysutil_deactivate_noblock(int fd);
/* This does SHUT_RDWR */
void vsf_sysutil_shutdown_failok(int fd);
diff --git a/utility.c b/utility.c
index 75e5bdd..5619a04 100644
--- a/utility.c
+++ b/utility.c
@@ -47,11 +47,13 @@ bug(const char* p_text)
{
vsf_log_die(p_text);
}
- vsf_sysutil_activate_noblock(VSFTP_COMMAND_FD);
- (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, "500 OOPS: ", 10);
- (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, p_text,
- vsf_sysutil_strlen(p_text));
- (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, "\r\n", 2);
+ if (vsf_sysutil_activate_noblock_no_die(VSFTP_COMMAND_FD) == 0)
+ {
+ (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, "500 OOPS: ", 10);
+ (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, p_text,
+ vsf_sysutil_strlen(p_text));
+ (void) vsf_sysutil_write_loop(VSFTP_COMMAND_FD, "\r\n", 2);
+ }
if (tunable_log_die)
{
/* Workaround for https://github.com/systemd/systemd/issues/2913 */
--
2.20.1

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@ -2,7 +2,7 @@
Name: vsftpd
Version: 3.0.3
Release: 30%{?dist}
Release: 31%{?dist}
Summary: Very Secure Ftp Daemon
# OpenSSL link exception
@ -87,6 +87,8 @@ Patch56: 0056-Log-die-calls-to-syslog.patch
Patch57: 0057-Improve-error-message-when-max-number-of-bind-attemp.patch
Patch58: 0058-Make-the-max-number-of-bind-retries-tunable.patch
Patch59: 0059-Fix-SEGFAULT-when-running-in-a-container-as-PID-1.patch
Patch61: 0001-Move-closing-standard-FDs-after-listen.patch
Patch62: 0002-Prevent-recursion-in-bug.patch
%description
vsftpd is a Very Secure FTP daemon. It was written completely from
@ -155,6 +157,10 @@ mkdir -p $RPM_BUILD_ROOT/%{_var}/ftp/pub
%{_var}/ftp
%changelog
* Sat Aug 03 2019 Ondřej Lysoněk <olysonek@redhat.com> - 3.0.3-31
- Fix segfault when listen() returns an error
- Resolves: rhbz#1666380
* Sat Jul 27 2019 Fedora Release Engineering <releng@fedoraproject.org> - 3.0.3-30
- Rebuilt for https://fedoraproject.org/wiki/Fedora_31_Mass_Rebuild