Mercurial > hg > nginx
view src/http/v2/ngx_http_v2_table.c @ 7094:c7d4017c8876
Secure link: fixed stack buffer overflow.
When secure link checksum has length of 23 or 24 bytes, decoded base64 value
could occupy 17 or 18 bytes which is more than 16 bytes previously allocated
for it on stack. The buffer overflow does not have any security implications
since only one local variable was corrupted and this variable was not used in
this case.
The fix is to increase buffer size up to 18 bytes. Useless buffer size
initialization is removed as well.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 22 Aug 2017 21:22:59 +0300 |
parents | 257b51c37c5a |
children | d4b031cf32cf |
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/* * Copyright (C) Nginx, Inc. * Copyright (C) Valentin V. Bartenev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #define NGX_HTTP_V2_TABLE_SIZE 4096 static ngx_int_t ngx_http_v2_table_account(ngx_http_v2_connection_t *h2c, size_t size); static ngx_http_v2_header_t ngx_http_v2_static_table[] = { { ngx_string(":authority"), ngx_string("") }, { ngx_string(":method"), ngx_string("GET") }, { ngx_string(":method"), ngx_string("POST") }, { ngx_string(":path"), ngx_string("/") }, { ngx_string(":path"), ngx_string("/index.html") }, { ngx_string(":scheme"), ngx_string("http") }, { ngx_string(":scheme"), ngx_string("https") }, { ngx_string(":status"), ngx_string("200") }, { ngx_string(":status"), ngx_string("204") }, { ngx_string(":status"), ngx_string("206") }, { ngx_string(":status"), ngx_string("304") }, { ngx_string(":status"), ngx_string("400") }, { ngx_string(":status"), ngx_string("404") }, { ngx_string(":status"), ngx_string("500") }, { ngx_string("accept-charset"), ngx_string("") }, { ngx_string("accept-encoding"), ngx_string("gzip, deflate") }, { ngx_string("accept-language"), ngx_string("") }, { ngx_string("accept-ranges"), ngx_string("") }, { ngx_string("accept"), ngx_string("") }, { ngx_string("access-control-allow-origin"), ngx_string("") }, { ngx_string("age"), ngx_string("") }, { ngx_string("allow"), ngx_string("") }, { ngx_string("authorization"), ngx_string("") }, { ngx_string("cache-control"), ngx_string("") }, { ngx_string("content-disposition"), ngx_string("") }, { ngx_string("content-encoding"), ngx_string("") }, { ngx_string("content-language"), ngx_string("") }, { ngx_string("content-length"), ngx_string("") }, { ngx_string("content-location"), ngx_string("") }, { ngx_string("content-range"), ngx_string("") }, { ngx_string("content-type"), ngx_string("") }, { ngx_string("cookie"), ngx_string("") }, { ngx_string("date"), ngx_string("") }, { ngx_string("etag"), ngx_string("") }, { ngx_string("expect"), ngx_string("") }, { ngx_string("expires"), ngx_string("") }, { ngx_string("from"), ngx_string("") }, { ngx_string("host"), ngx_string("") }, { ngx_string("if-match"), ngx_string("") }, { ngx_string("if-modified-since"), ngx_string("") }, { ngx_string("if-none-match"), ngx_string("") }, { ngx_string("if-range"), ngx_string("") }, { ngx_string("if-unmodified-since"), ngx_string("") }, { ngx_string("last-modified"), ngx_string("") }, { ngx_string("link"), ngx_string("") }, { ngx_string("location"), ngx_string("") }, { ngx_string("max-forwards"), ngx_string("") }, { ngx_string("proxy-authenticate"), ngx_string("") }, { ngx_string("proxy-authorization"), ngx_string("") }, { ngx_string("range"), ngx_string("") }, { ngx_string("referer"), ngx_string("") }, { ngx_string("refresh"), ngx_string("") }, { ngx_string("retry-after"), ngx_string("") }, { ngx_string("server"), ngx_string("") }, { ngx_string("set-cookie"), ngx_string("") }, { ngx_string("strict-transport-security"), ngx_string("") }, { ngx_string("transfer-encoding"), ngx_string("") }, { ngx_string("user-agent"), ngx_string("") }, { ngx_string("vary"), ngx_string("") }, { ngx_string("via"), ngx_string("") }, { ngx_string("www-authenticate"), ngx_string("") }, }; #define NGX_HTTP_V2_STATIC_TABLE_ENTRIES \ (sizeof(ngx_http_v2_static_table) \ / sizeof(ngx_http_v2_header_t)) ngx_int_t ngx_http_v2_get_indexed_header(ngx_http_v2_connection_t *h2c, ngx_uint_t index, ngx_uint_t name_only) { u_char *p; size_t rest; ngx_http_v2_header_t *entry; if (index == 0) { ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0, "client sent invalid hpack table index 0"); return NGX_ERROR; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 get indexed %s: %ui", name_only ? "header" : "header name", index); index--; if (index < NGX_HTTP_V2_STATIC_TABLE_ENTRIES) { h2c->state.header = ngx_http_v2_static_table[index]; return NGX_OK; } index -= NGX_HTTP_V2_STATIC_TABLE_ENTRIES; if (index < h2c->hpack.added - h2c->hpack.deleted) { index = (h2c->hpack.added - index - 1) % h2c->hpack.allocated; entry = h2c->hpack.entries[index]; p = ngx_pnalloc(h2c->state.pool, entry->name.len + 1); if (p == NULL) { return NGX_ERROR; } h2c->state.header.name.len = entry->name.len; h2c->state.header.name.data = p; rest = h2c->hpack.storage + NGX_HTTP_V2_TABLE_SIZE - entry->name.data; if (entry->name.len > rest) { p = ngx_cpymem(p, entry->name.data, rest); p = ngx_cpymem(p, h2c->hpack.storage, entry->name.len - rest); } else { p = ngx_cpymem(p, entry->name.data, entry->name.len); } *p = '\0'; if (name_only) { return NGX_OK; } p = ngx_pnalloc(h2c->state.pool, entry->value.len + 1); if (p == NULL) { return NGX_ERROR; } h2c->state.header.value.len = entry->value.len; h2c->state.header.value.data = p; rest = h2c->hpack.storage + NGX_HTTP_V2_TABLE_SIZE - entry->value.data; if (entry->value.len > rest) { p = ngx_cpymem(p, entry->value.data, rest); p = ngx_cpymem(p, h2c->hpack.storage, entry->value.len - rest); } else { p = ngx_cpymem(p, entry->value.data, entry->value.len); } *p = '\0'; return NGX_OK; } ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0, "client sent out of bound hpack table index: %ui", index); return NGX_ERROR; } ngx_int_t ngx_http_v2_add_header(ngx_http_v2_connection_t *h2c, ngx_http_v2_header_t *header) { size_t avail; ngx_uint_t index; ngx_http_v2_header_t *entry, **entries; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 add header to hpack table: \"%V: %V\"", &header->name, &header->value); if (h2c->hpack.entries == NULL) { h2c->hpack.allocated = 64; h2c->hpack.size = NGX_HTTP_V2_TABLE_SIZE; h2c->hpack.free = NGX_HTTP_V2_TABLE_SIZE; h2c->hpack.entries = ngx_palloc(h2c->connection->pool, sizeof(ngx_http_v2_header_t *) * h2c->hpack.allocated); if (h2c->hpack.entries == NULL) { return NGX_ERROR; } h2c->hpack.storage = ngx_palloc(h2c->connection->pool, h2c->hpack.free); if (h2c->hpack.storage == NULL) { return NGX_ERROR; } h2c->hpack.pos = h2c->hpack.storage; } if (ngx_http_v2_table_account(h2c, header->name.len + header->value.len) != NGX_OK) { return NGX_OK; } if (h2c->hpack.reused == h2c->hpack.deleted) { entry = ngx_palloc(h2c->connection->pool, sizeof(ngx_http_v2_header_t)); if (entry == NULL) { return NGX_ERROR; } } else { entry = h2c->hpack.entries[h2c->hpack.reused++ % h2c->hpack.allocated]; } avail = h2c->hpack.storage + NGX_HTTP_V2_TABLE_SIZE - h2c->hpack.pos; entry->name.len = header->name.len; entry->name.data = h2c->hpack.pos; if (avail >= header->name.len) { h2c->hpack.pos = ngx_cpymem(h2c->hpack.pos, header->name.data, header->name.len); } else { ngx_memcpy(h2c->hpack.pos, header->name.data, avail); h2c->hpack.pos = ngx_cpymem(h2c->hpack.storage, header->name.data + avail, header->name.len - avail); avail = NGX_HTTP_V2_TABLE_SIZE; } avail -= header->name.len; entry->value.len = header->value.len; entry->value.data = h2c->hpack.pos; if (avail >= header->value.len) { h2c->hpack.pos = ngx_cpymem(h2c->hpack.pos, header->value.data, header->value.len); } else { ngx_memcpy(h2c->hpack.pos, header->value.data, avail); h2c->hpack.pos = ngx_cpymem(h2c->hpack.storage, header->value.data + avail, header->value.len - avail); } if (h2c->hpack.allocated == h2c->hpack.added - h2c->hpack.deleted) { entries = ngx_palloc(h2c->connection->pool, sizeof(ngx_http_v2_header_t *) * (h2c->hpack.allocated + 64)); if (entries == NULL) { return NGX_ERROR; } index = h2c->hpack.deleted % h2c->hpack.allocated; ngx_memcpy(entries, &h2c->hpack.entries[index], (h2c->hpack.allocated - index) * sizeof(ngx_http_v2_header_t *)); ngx_memcpy(&entries[h2c->hpack.allocated - index], h2c->hpack.entries, index * sizeof(ngx_http_v2_header_t *)); (void) ngx_pfree(h2c->connection->pool, h2c->hpack.entries); h2c->hpack.entries = entries; h2c->hpack.added = h2c->hpack.allocated; h2c->hpack.deleted = 0; h2c->hpack.reused = 0; h2c->hpack.allocated += 64; } h2c->hpack.entries[h2c->hpack.added++ % h2c->hpack.allocated] = entry; return NGX_OK; } static ngx_int_t ngx_http_v2_table_account(ngx_http_v2_connection_t *h2c, size_t size) { ngx_http_v2_header_t *entry; size += 32; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 hpack table account: %uz free:%uz", size, h2c->hpack.free); if (size <= h2c->hpack.free) { h2c->hpack.free -= size; return NGX_OK; } if (size > h2c->hpack.size) { h2c->hpack.deleted = h2c->hpack.added; h2c->hpack.free = h2c->hpack.size; return NGX_DECLINED; } do { entry = h2c->hpack.entries[h2c->hpack.deleted++ % h2c->hpack.allocated]; h2c->hpack.free += 32 + entry->name.len + entry->value.len; } while (size > h2c->hpack.free); h2c->hpack.free -= size; return NGX_OK; } ngx_int_t ngx_http_v2_table_size(ngx_http_v2_connection_t *h2c, size_t size) { ssize_t needed; ngx_http_v2_header_t *entry; if (size > NGX_HTTP_V2_TABLE_SIZE) { ngx_log_error(NGX_LOG_INFO, h2c->connection->log, 0, "client sent invalid table size update: %uz", size); return NGX_ERROR; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, h2c->connection->log, 0, "http2 new hpack table size: %uz was:%uz", size, h2c->hpack.size); needed = h2c->hpack.size - size; while (needed > (ssize_t) h2c->hpack.free) { entry = h2c->hpack.entries[h2c->hpack.deleted++ % h2c->hpack.allocated]; h2c->hpack.free += 32 + entry->name.len + entry->value.len; } h2c->hpack.size = size; h2c->hpack.free -= needed; return NGX_OK; }