spawn: close all file descriptors before execve

No need to give whatever we're calling access to what we use
This commit is contained in:
moneromooo-monero 2018-10-16 18:08:36 +00:00
parent 5c85da5a73
commit c774392985
No known key found for this signature in database
GPG Key ID: 686F07454D6CEFC3
3 changed files with 25 additions and 0 deletions

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@ -38,6 +38,7 @@
#endif
#include "misc_log_ex.h"
#include "util.h"
#include "spawn.h"
namespace tools
@ -101,6 +102,8 @@ int spawn(const char *filename, const std::vector<std::string>& args, bool wait)
// child
if (pid == 0)
{
tools::closefrom(3);
close(0);
char *envp[] = {NULL};
execve(filename, argv, envp);
MERROR("Failed to execve: " << strerror(errno));

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@ -28,6 +28,7 @@
//
// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
#include <unistd.h>
#include <cstdio>
#ifdef __GLIBC__
@ -967,4 +968,23 @@ std::string get_nix_version_display_string()
}
#endif
void closefrom(int fd)
{
#if defined __FreeBSD__ || defined __OpenBSD__ || defined __NetBSD__ || defined __DragonFly__
::closefrom(fd);
#else
#if defined __GLIBC__
const int sc_open_max = sysconf(_SC_OPEN_MAX);
const int MAX_FDS = std::min(65536, sc_open_max);
#else
const int MAX_FDS = 65536;
#endif
while (fd < MAX_FDS)
{
close(fd);
++fd;
}
#endif
}
}

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@ -238,4 +238,6 @@ namespace tools
#ifdef _WIN32
std::string input_line_win();
#endif
void closefrom(int fd);
}