[Asterisk-code-review] dns core: Protect against array index violation. (asterisk[15])

[Corey Farrell]

Corey Farrell has uploaded this change for review. ( https://gerrit.asterisk.org/7667


Change subject: dns_core: Protect against array index violation.
......................................................................

dns_core: Protect against array index violation.

Add a check to allocate_dns_record to prevent calling a pointer
retrieved from beyond dns_alloc_table.

ASTERISK-27495 #close

Change-Id: Ie2f6e4991cea46baa12e837bd64cc22b44d322bb
---
M main/dns_core.c
1 file changed, 5 insertions(+), 1 deletion(-)



  git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/67/7667/1

diff --git a/main/dns_core.c b/main/dns_core.c
index a243b4b..8ce8b9f 100644
--- a/main/dns_core.c
+++ b/main/dns_core.c
@@ -449,7 +449,11 @@
 
 static struct ast_dns_record *allocate_dns_record(int rr_type, struct ast_dns_query *query, const char *data, const size_t size)
 {
-	dns_alloc_fn allocator = dns_alloc_table[rr_type] ?: generic_record_alloc;
+	dns_alloc_fn allocator = generic_record_alloc;
+
+	if (rr_type < ARRAY_LEN(dns_alloc_table) && dns_alloc_table[rr_type]) {
+		allocator = dns_alloc_table[rr_type];
+	}
 
 	return allocator(query, data, size);
 }

-- 
To view, visit https://gerrit.asterisk.org/7667
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Gerrit-Project: asterisk
Gerrit-Branch: 15
Gerrit-MessageType: newchange
Gerrit-Change-Id: Ie2f6e4991cea46baa12e837bd64cc22b44d322bb
Gerrit-Change-Number: 7667
Gerrit-PatchSet: 1
Gerrit-Owner: Corey Farrell <git at cfware.com>
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