Avoid null pointer dereference crash after OOM in Snowball stemmers.

tglsfdc · tglsfdc · commit 7edd2cbc535c · 2025-02-18T21:23:59.000-05:00
Absorb upstream bug fix (their commit e322673a841d9abd69994ae8cd20e191090b6ef4), which prevents a null pointer dereference crash if SN_create_env() gets a malloc failure at just the wrong point. Thanks to Maksim Korotkov for discovering the null-pointer bug and submitting the fix to upstream snowball. Reported-by: Maksim Korotkov <m.korotkov@postgrespro.ru> Author: Maksim Korotkov <m.korotkov@postgrespro.ru> Discussion: https://postgr.es/m/1d1a46-67ab1000-21-80c451@83151435 Backpatch-through: 13
diff --git a/src/backend/snowball/libstemmer/api.c b/src/backend/snowball/libstemmer/api.c
@@ -34,7 +34,7 @@ extern struct SN_env * SN_create_env(int S_size, int I_size)
 extern void SN_close_env(struct SN_env * z, int S_size)
 {
     if (z == NULL) return;
-    if (S_size)
+    if (z->S)
     {
         int i;
         for (i = 0; i < S_size; i++)

Original file line number	Diff line number	Diff line change
`@@ -34,7 +34,7 @@ extern struct SN_env * SN_create_env(int S_size, int I_size)`
`34`	`34`	`extern void SN_close_env(struct SN_env * z, int S_size)`
`35`	`35`	`{`
`36`	`36`	`if (z == NULL) return;`
`37`		`- if (S_size)`
	`37`	`+ if (z->S)`
`38`	`38`	`{`
`39`	`39`	`int i;`
`40`	`40`	`for (i = 0; i < S_size; i++)`