Mercurial > hg > nginx-quic
view src/core/ngx_buf.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 | d620f497c50f |
children | f9c83484d9ce |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> ngx_buf_t * ngx_create_temp_buf(ngx_pool_t *pool, size_t size) { ngx_buf_t *b; b = ngx_calloc_buf(pool); if (b == NULL) { return NULL; } b->start = ngx_palloc(pool, size); if (b->start == NULL) { return NULL; } /* * set by ngx_calloc_buf(): * * b->file_pos = 0; * b->file_last = 0; * b->file = NULL; * b->shadow = NULL; * b->tag = 0; * and flags */ b->pos = b->start; b->last = b->start; b->end = b->last + size; b->temporary = 1; return b; } ngx_chain_t * ngx_alloc_chain_link(ngx_pool_t *pool) { ngx_chain_t *cl; cl = pool->chain; if (cl) { pool->chain = cl->next; return cl; } cl = ngx_palloc(pool, sizeof(ngx_chain_t)); if (cl == NULL) { return NULL; } return cl; } ngx_chain_t * ngx_create_chain_of_bufs(ngx_pool_t *pool, ngx_bufs_t *bufs) { u_char *p; ngx_int_t i; ngx_buf_t *b; ngx_chain_t *chain, *cl, **ll; p = ngx_palloc(pool, bufs->num * bufs->size); if (p == NULL) { return NULL; } ll = &chain; for (i = 0; i < bufs->num; i++) { b = ngx_calloc_buf(pool); if (b == NULL) { return NULL; } /* * set by ngx_calloc_buf(): * * b->file_pos = 0; * b->file_last = 0; * b->file = NULL; * b->shadow = NULL; * b->tag = 0; * and flags * */ b->pos = p; b->last = p; b->temporary = 1; b->start = p; p += bufs->size; b->end = p; cl = ngx_alloc_chain_link(pool); if (cl == NULL) { return NULL; } cl->buf = b; *ll = cl; ll = &cl->next; } *ll = NULL; return chain; } ngx_int_t ngx_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain, ngx_chain_t *in) { ngx_chain_t *cl, **ll; ll = chain; for (cl = *chain; cl; cl = cl->next) { ll = &cl->next; } while (in) { cl = ngx_alloc_chain_link(pool); if (cl == NULL) { return NGX_ERROR; } cl->buf = in->buf; *ll = cl; ll = &cl->next; in = in->next; } *ll = NULL; return NGX_OK; } ngx_chain_t * ngx_chain_get_free_buf(ngx_pool_t *p, ngx_chain_t **free) { ngx_chain_t *cl; if (*free) { cl = *free; *free = cl->next; cl->next = NULL; return cl; } cl = ngx_alloc_chain_link(p); if (cl == NULL) { return NULL; } cl->buf = ngx_calloc_buf(p); if (cl->buf == NULL) { return NULL; } cl->next = NULL; return cl; } void ngx_chain_update_chains(ngx_pool_t *p, ngx_chain_t **free, ngx_chain_t **busy, ngx_chain_t **out, ngx_buf_tag_t tag) { ngx_chain_t *cl; if (*busy == NULL) { *busy = *out; } else { for (cl = *busy; cl->next; cl = cl->next) { /* void */ } cl->next = *out; } *out = NULL; while (*busy) { cl = *busy; if (ngx_buf_size(cl->buf) != 0) { break; } if (cl->buf->tag != tag) { *busy = cl->next; ngx_free_chain(p, cl); continue; } cl->buf->pos = cl->buf->start; cl->buf->last = cl->buf->start; *busy = cl->next; cl->next = *free; *free = cl; } }