view src/os/unix/ngx_process.h @ 9112:d59277dd3d8c

QUIC: fixed post-close use-after-free. Previously, ngx_quic_close_connection() could be called in a way that QUIC connection was accessed after the call. In most cases the connection is not closed right away, but close timeout is scheduled. However, it's not always the case. Also, if the close process started earlier for a different reason, calling ngx_quic_close_connection() may actually close the connection. The connection object should not be accessed after that. Now, when possible, return statement is added to eliminate post-close connection object access. In other places ngx_quic_close_connection() is substituted with posting close event. Also, the new way of closing connection in ngx_quic_stream_cleanup_handler() fixes another problem in this function. Previously it passed stream connection instead of QUIC connection to ngx_quic_close_connection(). This could result in incomplete connection shutdown. One consequence of that could be that QUIC streams were freed without shutting down their application contexts. This could result in another use-after-free. Found by Coverity (CID 1530402).
author Roman Arutyunyan <arut@nginx.com>
date Mon, 22 May 2023 15:59:42 +0400
parents 8b84d60ef13d
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_PROCESS_H_INCLUDED_
#define _NGX_PROCESS_H_INCLUDED_


#include <ngx_setaffinity.h>
#include <ngx_setproctitle.h>


typedef pid_t       ngx_pid_t;

#define NGX_INVALID_PID  -1

typedef void (*ngx_spawn_proc_pt) (ngx_cycle_t *cycle, void *data);

typedef struct {
    ngx_pid_t           pid;
    int                 status;
    ngx_socket_t        channel[2];

    ngx_spawn_proc_pt   proc;
    void               *data;
    char               *name;

    unsigned            respawn:1;
    unsigned            just_spawn:1;
    unsigned            detached:1;
    unsigned            exiting:1;
    unsigned            exited:1;
} ngx_process_t;


typedef struct {
    char         *path;
    char         *name;
    char *const  *argv;
    char *const  *envp;
} ngx_exec_ctx_t;


#define NGX_MAX_PROCESSES         1024

#define NGX_PROCESS_NORESPAWN     -1
#define NGX_PROCESS_JUST_SPAWN    -2
#define NGX_PROCESS_RESPAWN       -3
#define NGX_PROCESS_JUST_RESPAWN  -4
#define NGX_PROCESS_DETACHED      -5


#define ngx_getpid   getpid
#define ngx_getppid  getppid

#ifndef ngx_log_pid
#define ngx_log_pid  ngx_pid
#endif


ngx_pid_t ngx_spawn_process(ngx_cycle_t *cycle,
    ngx_spawn_proc_pt proc, void *data, char *name, ngx_int_t respawn);
ngx_pid_t ngx_execute(ngx_cycle_t *cycle, ngx_exec_ctx_t *ctx);
ngx_int_t ngx_init_signals(ngx_log_t *log);
void ngx_debug_point(void);


#if (NGX_HAVE_SCHED_YIELD)
#define ngx_sched_yield()  sched_yield()
#else
#define ngx_sched_yield()  usleep(1)
#endif


extern int            ngx_argc;
extern char         **ngx_argv;
extern char         **ngx_os_argv;

extern ngx_pid_t      ngx_pid;
extern ngx_pid_t      ngx_parent;
extern ngx_socket_t   ngx_channel;
extern ngx_int_t      ngx_process_slot;
extern ngx_int_t      ngx_last_process;
extern ngx_process_t  ngx_processes[NGX_MAX_PROCESSES];


#endif /* _NGX_PROCESS_H_INCLUDED_ */