Mercurial > hg > nginx-quic
view src/http/ngx_http_spdy.h @ 6359:dac6eda40475 stable-1.8
Resolver: fixed use-after-free memory accesses with CNAME.
When several requests were waiting for a response, then after getting
a CNAME response only the last request's context had the name updated.
Contexts of other requests had the wrong name. This name was used by
ngx_resolve_name_done() to find the node to remove the request context
from. When the name was wrong, the request could not be properly
cancelled, its context was freed but stayed linked to the node's waiting
list. This happened e.g. when the first request was aborted or timed
out before the resolving completed. When it completed, this triggered
a use-after-free memory access by calling ctx->handler of already freed
request context. The bug manifests itself by
"could not cancel <name> resolving" alerts in error_log.
When a request was responded with a CNAME, the request context kept
the pointer to the original node's rn->u.cname. If the original node
expired before the resolving timed out or completed with an error,
this would trigger a use-after-free memory access via ctx->name in
ctx->handler().
The fix is to keep ctx->name unmodified. The name from context
is no longer used by ngx_resolve_name_done(). Instead, we now keep
the pointer to resolver node to which this request is linked.
Keeping the original name intact also improves logging.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 26 Jan 2016 16:46:59 +0300 |
parents | 34d460c5d186 |
children |
line wrap: on
line source
/* * Copyright (C) Nginx, Inc. * Copyright (C) Valentin V. Bartenev */ #ifndef _NGX_HTTP_SPDY_H_INCLUDED_ #define _NGX_HTTP_SPDY_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #include <zlib.h> #define NGX_SPDY_VERSION 3 #define NGX_SPDY_NPN_ADVERTISE "\x08spdy/3.1" #define NGX_SPDY_NPN_NEGOTIATED "spdy/3.1" #define NGX_SPDY_STATE_BUFFER_SIZE 16 #define NGX_SPDY_CTL_BIT 1 #define NGX_SPDY_SYN_STREAM 1 #define NGX_SPDY_SYN_REPLY 2 #define NGX_SPDY_RST_STREAM 3 #define NGX_SPDY_SETTINGS 4 #define NGX_SPDY_PING 6 #define NGX_SPDY_GOAWAY 7 #define NGX_SPDY_HEADERS 8 #define NGX_SPDY_WINDOW_UPDATE 9 #define NGX_SPDY_FRAME_HEADER_SIZE 8 #define NGX_SPDY_SID_SIZE 4 #define NGX_SPDY_DELTA_SIZE 4 #define NGX_SPDY_SYN_STREAM_SIZE 10 #define NGX_SPDY_SYN_REPLY_SIZE 4 #define NGX_SPDY_RST_STREAM_SIZE 8 #define NGX_SPDY_PING_SIZE 4 #define NGX_SPDY_GOAWAY_SIZE 8 #define NGX_SPDY_WINDOW_UPDATE_SIZE 8 #define NGX_SPDY_NV_NUM_SIZE 4 #define NGX_SPDY_NV_NLEN_SIZE 4 #define NGX_SPDY_NV_VLEN_SIZE 4 #define NGX_SPDY_SETTINGS_NUM_SIZE 4 #define NGX_SPDY_SETTINGS_FID_SIZE 4 #define NGX_SPDY_SETTINGS_VAL_SIZE 4 #define NGX_SPDY_SETTINGS_PAIR_SIZE \ (NGX_SPDY_SETTINGS_FID_SIZE + NGX_SPDY_SETTINGS_VAL_SIZE) #define NGX_SPDY_HIGHEST_PRIORITY 0 #define NGX_SPDY_LOWEST_PRIORITY 7 #define NGX_SPDY_FLAG_FIN 0x01 #define NGX_SPDY_FLAG_UNIDIRECTIONAL 0x02 #define NGX_SPDY_FLAG_CLEAR_SETTINGS 0x01 #define NGX_SPDY_MAX_FRAME_SIZE ((1 << 24) - 1) #define NGX_SPDY_DATA_DISCARD 1 #define NGX_SPDY_DATA_ERROR 2 #define NGX_SPDY_DATA_INTERNAL_ERROR 3 typedef struct ngx_http_spdy_connection_s ngx_http_spdy_connection_t; typedef struct ngx_http_spdy_out_frame_s ngx_http_spdy_out_frame_t; typedef u_char *(*ngx_http_spdy_handler_pt) (ngx_http_spdy_connection_t *sc, u_char *pos, u_char *end); struct ngx_http_spdy_connection_s { ngx_connection_t *connection; ngx_http_connection_t *http_connection; ngx_uint_t processing; size_t send_window; size_t recv_window; size_t init_window; ngx_queue_t waiting; u_char buffer[NGX_SPDY_STATE_BUFFER_SIZE]; size_t buffer_used; ngx_http_spdy_handler_pt handler; z_stream zstream_in; z_stream zstream_out; ngx_pool_t *pool; ngx_http_spdy_out_frame_t *free_ctl_frames; ngx_connection_t *free_fake_connections; ngx_http_spdy_stream_t **streams_index; ngx_http_spdy_out_frame_t *last_out; ngx_queue_t posted; ngx_http_spdy_stream_t *stream; ngx_uint_t entries; size_t length; u_char flags; ngx_uint_t last_sid; unsigned blocked:1; unsigned incomplete:1; }; struct ngx_http_spdy_stream_s { ngx_uint_t id; ngx_http_request_t *request; ngx_http_spdy_connection_t *connection; ngx_http_spdy_stream_t *index; ngx_uint_t header_buffers; ngx_uint_t queued; /* * A change to SETTINGS_INITIAL_WINDOW_SIZE could cause the * send_window to become negative, hence it's signed. */ ssize_t send_window; size_t recv_window; ngx_http_spdy_out_frame_t *free_frames; ngx_chain_t *free_data_headers; ngx_chain_t *free_bufs; ngx_queue_t queue; unsigned priority:3; unsigned handled:1; unsigned blocked:1; unsigned exhausted:1; unsigned in_closed:1; unsigned out_closed:1; unsigned skip_data:2; }; struct ngx_http_spdy_out_frame_s { ngx_http_spdy_out_frame_t *next; ngx_chain_t *first; ngx_chain_t *last; ngx_int_t (*handler)(ngx_http_spdy_connection_t *sc, ngx_http_spdy_out_frame_t *frame); ngx_http_spdy_stream_t *stream; size_t length; ngx_uint_t priority; unsigned blocked:1; unsigned fin:1; }; static ngx_inline void ngx_http_spdy_queue_frame(ngx_http_spdy_connection_t *sc, ngx_http_spdy_out_frame_t *frame) { ngx_http_spdy_out_frame_t **out; for (out = &sc->last_out; *out; out = &(*out)->next) { /* * NB: higher values represent lower priorities. */ if (frame->priority >= (*out)->priority) { break; } } frame->next = *out; *out = frame; } static ngx_inline void ngx_http_spdy_queue_blocked_frame(ngx_http_spdy_connection_t *sc, ngx_http_spdy_out_frame_t *frame) { ngx_http_spdy_out_frame_t **out; for (out = &sc->last_out; *out; out = &(*out)->next) { if ((*out)->blocked) { break; } } frame->next = *out; *out = frame; } void ngx_http_spdy_init(ngx_event_t *rev); void ngx_http_spdy_request_headers_init(void); ngx_int_t ngx_http_spdy_read_request_body(ngx_http_request_t *r, ngx_http_client_body_handler_pt post_handler); void ngx_http_spdy_close_stream(ngx_http_spdy_stream_t *stream, ngx_int_t rc); ngx_int_t ngx_http_spdy_send_output_queue(ngx_http_spdy_connection_t *sc); #define ngx_spdy_frame_aligned_write_uint16(p, s) \ (*(uint16_t *) (p) = htons((uint16_t) (s)), (p) + sizeof(uint16_t)) #define ngx_spdy_frame_aligned_write_uint32(p, s) \ (*(uint32_t *) (p) = htonl((uint32_t) (s)), (p) + sizeof(uint32_t)) #if (NGX_HAVE_NONALIGNED) #define ngx_spdy_frame_write_uint16 ngx_spdy_frame_aligned_write_uint16 #define ngx_spdy_frame_write_uint32 ngx_spdy_frame_aligned_write_uint32 #else #define ngx_spdy_frame_write_uint16(p, s) \ ((p)[0] = (u_char) ((s) >> 8), \ (p)[1] = (u_char) (s), \ (p) + sizeof(uint16_t)) #define ngx_spdy_frame_write_uint32(p, s) \ ((p)[0] = (u_char) ((s) >> 24), \ (p)[1] = (u_char) ((s) >> 16), \ (p)[2] = (u_char) ((s) >> 8), \ (p)[3] = (u_char) (s), \ (p) + sizeof(uint32_t)) #endif #define ngx_spdy_ctl_frame_head(t) \ ((uint32_t) NGX_SPDY_CTL_BIT << 31 | NGX_SPDY_VERSION << 16 | (t)) #define ngx_spdy_frame_write_head(p, t) \ ngx_spdy_frame_aligned_write_uint32(p, ngx_spdy_ctl_frame_head(t)) #define ngx_spdy_frame_write_flags_and_len(p, f, l) \ ngx_spdy_frame_aligned_write_uint32(p, (f) << 24 | (l)) #define ngx_spdy_frame_write_flags_and_id(p, f, i) \ ngx_spdy_frame_aligned_write_uint32(p, (f) << 24 | (i)) #define ngx_spdy_frame_write_sid ngx_spdy_frame_aligned_write_uint32 #define ngx_spdy_frame_write_window ngx_spdy_frame_aligned_write_uint32 #endif /* _NGX_HTTP_SPDY_H_INCLUDED_ */