Mercurial > hg > nginx
view src/core/ngx_rbtree.c @ 7667:1ece2ac2555a
OCSP: fixed use-after-free on error.
When validating second and further certificates, ssl callback could be called
twice to report the error. After the first call client connection is
terminated and its memory is released. Prior to the second call and in it
released connection memory is accessed.
Errors triggering this behavior:
- failure to create the request
- failure to start resolving OCSP responder name
- failure to start connecting to the OCSP responder
The fix is to rearrange the code to eliminate the second call.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 15 Jun 2020 20:17:16 +0300 |
parents | 7fdcf308e0f0 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> /* * The red-black tree code is based on the algorithm described in * the "Introduction to Algorithms" by Cormen, Leiserson and Rivest. */ static ngx_inline void ngx_rbtree_left_rotate(ngx_rbtree_node_t **root, ngx_rbtree_node_t *sentinel, ngx_rbtree_node_t *node); static ngx_inline void ngx_rbtree_right_rotate(ngx_rbtree_node_t **root, ngx_rbtree_node_t *sentinel, ngx_rbtree_node_t *node); void ngx_rbtree_insert(ngx_rbtree_t *tree, ngx_rbtree_node_t *node) { ngx_rbtree_node_t **root, *temp, *sentinel; /* a binary tree insert */ root = &tree->root; sentinel = tree->sentinel; if (*root == sentinel) { node->parent = NULL; node->left = sentinel; node->right = sentinel; ngx_rbt_black(node); *root = node; return; } tree->insert(*root, node, sentinel); /* re-balance tree */ while (node != *root && ngx_rbt_is_red(node->parent)) { if (node->parent == node->parent->parent->left) { temp = node->parent->parent->right; if (ngx_rbt_is_red(temp)) { ngx_rbt_black(node->parent); ngx_rbt_black(temp); ngx_rbt_red(node->parent->parent); node = node->parent->parent; } else { if (node == node->parent->right) { node = node->parent; ngx_rbtree_left_rotate(root, sentinel, node); } ngx_rbt_black(node->parent); ngx_rbt_red(node->parent->parent); ngx_rbtree_right_rotate(root, sentinel, node->parent->parent); } } else { temp = node->parent->parent->left; if (ngx_rbt_is_red(temp)) { ngx_rbt_black(node->parent); ngx_rbt_black(temp); ngx_rbt_red(node->parent->parent); node = node->parent->parent; } else { if (node == node->parent->left) { node = node->parent; ngx_rbtree_right_rotate(root, sentinel, node); } ngx_rbt_black(node->parent); ngx_rbt_red(node->parent->parent); ngx_rbtree_left_rotate(root, sentinel, node->parent->parent); } } } ngx_rbt_black(*root); } void ngx_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_rbtree_node_t **p; for ( ;; ) { p = (node->key < temp->key) ? &temp->left : &temp->right; if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } void ngx_rbtree_insert_timer_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_rbtree_node_t **p; for ( ;; ) { /* * Timer values * 1) are spread in small range, usually several minutes, * 2) and overflow each 49 days, if milliseconds are stored in 32 bits. * The comparison takes into account that overflow. */ /* node->key < temp->key */ p = ((ngx_rbtree_key_int_t) (node->key - temp->key) < 0) ? &temp->left : &temp->right; if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } void ngx_rbtree_delete(ngx_rbtree_t *tree, ngx_rbtree_node_t *node) { ngx_uint_t red; ngx_rbtree_node_t **root, *sentinel, *subst, *temp, *w; /* a binary tree delete */ root = &tree->root; sentinel = tree->sentinel; if (node->left == sentinel) { temp = node->right; subst = node; } else if (node->right == sentinel) { temp = node->left; subst = node; } else { subst = ngx_rbtree_min(node->right, sentinel); temp = subst->right; } if (subst == *root) { *root = temp; ngx_rbt_black(temp); /* DEBUG stuff */ node->left = NULL; node->right = NULL; node->parent = NULL; node->key = 0; return; } red = ngx_rbt_is_red(subst); if (subst == subst->parent->left) { subst->parent->left = temp; } else { subst->parent->right = temp; } if (subst == node) { temp->parent = subst->parent; } else { if (subst->parent == node) { temp->parent = subst; } else { temp->parent = subst->parent; } subst->left = node->left; subst->right = node->right; subst->parent = node->parent; ngx_rbt_copy_color(subst, node); if (node == *root) { *root = subst; } else { if (node == node->parent->left) { node->parent->left = subst; } else { node->parent->right = subst; } } if (subst->left != sentinel) { subst->left->parent = subst; } if (subst->right != sentinel) { subst->right->parent = subst; } } /* DEBUG stuff */ node->left = NULL; node->right = NULL; node->parent = NULL; node->key = 0; if (red) { return; } /* a delete fixup */ while (temp != *root && ngx_rbt_is_black(temp)) { if (temp == temp->parent->left) { w = temp->parent->right; if (ngx_rbt_is_red(w)) { ngx_rbt_black(w); ngx_rbt_red(temp->parent); ngx_rbtree_left_rotate(root, sentinel, temp->parent); w = temp->parent->right; } if (ngx_rbt_is_black(w->left) && ngx_rbt_is_black(w->right)) { ngx_rbt_red(w); temp = temp->parent; } else { if (ngx_rbt_is_black(w->right)) { ngx_rbt_black(w->left); ngx_rbt_red(w); ngx_rbtree_right_rotate(root, sentinel, w); w = temp->parent->right; } ngx_rbt_copy_color(w, temp->parent); ngx_rbt_black(temp->parent); ngx_rbt_black(w->right); ngx_rbtree_left_rotate(root, sentinel, temp->parent); temp = *root; } } else { w = temp->parent->left; if (ngx_rbt_is_red(w)) { ngx_rbt_black(w); ngx_rbt_red(temp->parent); ngx_rbtree_right_rotate(root, sentinel, temp->parent); w = temp->parent->left; } if (ngx_rbt_is_black(w->left) && ngx_rbt_is_black(w->right)) { ngx_rbt_red(w); temp = temp->parent; } else { if (ngx_rbt_is_black(w->left)) { ngx_rbt_black(w->right); ngx_rbt_red(w); ngx_rbtree_left_rotate(root, sentinel, w); w = temp->parent->left; } ngx_rbt_copy_color(w, temp->parent); ngx_rbt_black(temp->parent); ngx_rbt_black(w->left); ngx_rbtree_right_rotate(root, sentinel, temp->parent); temp = *root; } } } ngx_rbt_black(temp); } static ngx_inline void ngx_rbtree_left_rotate(ngx_rbtree_node_t **root, ngx_rbtree_node_t *sentinel, ngx_rbtree_node_t *node) { ngx_rbtree_node_t *temp; temp = node->right; node->right = temp->left; if (temp->left != sentinel) { temp->left->parent = node; } temp->parent = node->parent; if (node == *root) { *root = temp; } else if (node == node->parent->left) { node->parent->left = temp; } else { node->parent->right = temp; } temp->left = node; node->parent = temp; } static ngx_inline void ngx_rbtree_right_rotate(ngx_rbtree_node_t **root, ngx_rbtree_node_t *sentinel, ngx_rbtree_node_t *node) { ngx_rbtree_node_t *temp; temp = node->left; node->left = temp->right; if (temp->right != sentinel) { temp->right->parent = node; } temp->parent = node->parent; if (node == *root) { *root = temp; } else if (node == node->parent->right) { node->parent->right = temp; } else { node->parent->left = temp; } temp->right = node; node->parent = temp; } ngx_rbtree_node_t * ngx_rbtree_next(ngx_rbtree_t *tree, ngx_rbtree_node_t *node) { ngx_rbtree_node_t *root, *sentinel, *parent; sentinel = tree->sentinel; if (node->right != sentinel) { return ngx_rbtree_min(node->right, sentinel); } root = tree->root; for ( ;; ) { parent = node->parent; if (node == root) { return NULL; } if (node == parent->left) { return parent; } node = parent; } }