ComputerSurge/bind9
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Don't perform arithmetic on NULL pointers

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When node is NULL when calling getparent() et al. they return NULL
but performing arithmetic on the NULL pointer is undefined.  Check
if 'node' or 'header' is NULL and skip the adjustment.
This commit is contained in:
Mark Andrews
2023-01-10 17:15:09 +11:00
parent 802f700d5a
commit 2a9300a3bc
1 changed files with 14 additions and 5 deletions
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19
lib/dns/rbt.c
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@@ -168,6 +168,10 @@ serialize_nodes(FILE *file, dns_rbtnode_t *node, uintptr_t parent,
dns_rbtdatawriter_t datawriter, void *writer_arg,
uintptr_t *where, uint64_t *crc);
#define ADJUST_ADDRESS(address, relative, header) \
if (address != NULL && header != NULL) { \
address += relative * (uintptr_t)header; \
}
/*
* The following functions allow you to get the actual address of a pointer
* without having to use an if statement to check to see if that address is
@@ -176,7 +180,8 @@ serialize_nodes(FILE *file, dns_rbtnode_t *node, uintptr_t parent,
static dns_rbtnode_t *
getparent(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->parent);
adjusted_address += node->parent_is_relative * (uintptr_t)header;
ADJUST_ADDRESS(adjusted_address, node->parent_is_relative, header);
return ((dns_rbtnode_t *)adjusted_address);
}
@@ -184,7 +189,8 @@ getparent(dns_rbtnode_t *node, file_header_t *header) {
static dns_rbtnode_t *
getleft(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->left);
adjusted_address += node->left_is_relative * (uintptr_t)header;
ADJUST_ADDRESS(adjusted_address, node->left_is_relative, header);
return ((dns_rbtnode_t *)adjusted_address);
}
@@ -192,7 +198,8 @@ getleft(dns_rbtnode_t *node, file_header_t *header) {
static dns_rbtnode_t *
getright(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->right);
adjusted_address += node->right_is_relative * (uintptr_t)header;
ADJUST_ADDRESS(adjusted_address, node->right_is_relative, header);
return ((dns_rbtnode_t *)adjusted_address);
}
@@ -200,7 +207,8 @@ getright(dns_rbtnode_t *node, file_header_t *header) {
static dns_rbtnode_t *
getdown(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->down);
adjusted_address += node->down_is_relative * (uintptr_t)header;
ADJUST_ADDRESS(adjusted_address, node->down_is_relative, header);
return ((dns_rbtnode_t *)adjusted_address);
}
@@ -208,7 +216,8 @@ getdown(dns_rbtnode_t *node, file_header_t *header) {
static dns_rbtnode_t *
getdata(dns_rbtnode_t *node, file_header_t *header) {
char *adjusted_address = (char *)(node->data);
adjusted_address += node->data_is_relative * (uintptr_t)header;
ADJUST_ADDRESS(adjusted_address, node->data_is_relative, header);
return ((dns_rbtnode_t *)adjusted_address);
}