view src/os/unix/ngx_thread_id.c @ 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 466bd63b63d1
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_thread_pool.h>


#if (NGX_LINUX)

/*
 * Linux thread id is a pid of thread created by clone(2),
 * glibc does not provide a wrapper for gettid().
 */

ngx_tid_t
ngx_thread_tid(void)
{
    return syscall(SYS_gettid);
}

#elif (NGX_FREEBSD) && (__FreeBSD_version >= 900031)

#include <pthread_np.h>

ngx_tid_t
ngx_thread_tid(void)
{
    return pthread_getthreadid_np();
}

#elif (NGX_DARWIN)

/*
 * MacOSX thread has two thread ids:
 *
 * 1) MacOSX 10.6 (Snow Leoprad) has pthread_threadid_np() returning
 *    an uint64_t value, which is obtained using the __thread_selfid()
 *    syscall.  It is a number above 300,000.
 */

ngx_tid_t
ngx_thread_tid(void)
{
    uint64_t  tid;

    (void) pthread_threadid_np(NULL, &tid);
    return tid;
}

/*
 * 2) Kernel thread mach_port_t returned by pthread_mach_thread_np().
 *    It is a number in range 100-100,000.
 *
 * return pthread_mach_thread_np(pthread_self());
 */

#else

ngx_tid_t
ngx_thread_tid(void)
{
    return (uint64_t) (uintptr_t) pthread_self();
}

#endif