Mercurial > hg > nginx-quic
view src/os/unix/ngx_errno.c @ 4964:2464ccebdb52
Upstream: fixed SIGSEGV with the "if" directive.
Configuration like
location / {
set $true 1;
if ($true) {
proxy_pass http://backend;
}
if ($true) {
# nothing
}
}
resulted in segmentation fault due to NULL pointer dereference as the
upstream configuration wasn't initialized in an implicit location created
by the last if(), but the r->content_handler was set due to first if().
Instead of committing a suicide by dereferencing a NULL pointer, return
500 (Internal Server Error) in such cases, i.e. if uscf is NULL. Better
fix would be to avoid such cases by fixing the "if" directive handling,
but it's out of scope of this patch.
Prodded by Piotr Sikora.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 13 Dec 2012 16:05:59 +0000 |
parents | f1a0de6eb505 |
children | 8cc5b0365ee5 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> /* * The strerror() messages are copied because: * * 1) strerror() and strerror_r() functions are not Async-Signal-Safe, * therefore, they cannot be used in signal handlers; * * 2) a direct sys_errlist[] array may be used instead of these functions, * but Linux linker warns about its usage: * * warning: `sys_errlist' is deprecated; use `strerror' or `strerror_r' instead * warning: `sys_nerr' is deprecated; use `strerror' or `strerror_r' instead * * causing false bug reports. */ static ngx_str_t *ngx_sys_errlist; static ngx_str_t ngx_unknown_error = ngx_string("Unknown error"); u_char * ngx_strerror(ngx_err_t err, u_char *errstr, size_t size) { ngx_str_t *msg; msg = ((ngx_uint_t) err < NGX_SYS_NERR) ? &ngx_sys_errlist[err]: &ngx_unknown_error; size = ngx_min(size, msg->len); return ngx_cpymem(errstr, msg->data, size); } ngx_int_t ngx_strerror_init(void) { char *msg; u_char *p; size_t len; ngx_err_t err; /* * ngx_strerror() is not ready to work at this stage, therefore, * malloc() is used and possible errors are logged using strerror(). */ len = NGX_SYS_NERR * sizeof(ngx_str_t); ngx_sys_errlist = malloc(len); if (ngx_sys_errlist == NULL) { goto failed; } for (err = 0; err < NGX_SYS_NERR; err++) { msg = strerror(err); len = ngx_strlen(msg); p = malloc(len); if (p == NULL) { goto failed; } ngx_memcpy(p, msg, len); ngx_sys_errlist[err].len = len; ngx_sys_errlist[err].data = p; } return NGX_OK; failed: err = errno; ngx_log_stderr(0, "malloc(%uz) failed (%d: %s)", len, err, strerror(err)); return NGX_ERROR; }