Avoid null pointer dereference crash after OOM in Snowball stemmers.

tglsfdc · tglsfdc · commit 197427fb3f0b · 2025-02-18T21:24:12.000-05:00
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
@@ -40,7 +40,7 @@ extern struct SN_env * SN_create_env(int S_size, int I_size, int B_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
`@@ -40,7 +40,7 @@ extern struct SN_env * SN_create_env(int S_size, int I_size, int B_size)`
`40`	`40`	`extern void SN_close_env(struct SN_env * z, int S_size)`
`41`	`41`	`{`
`42`	`42`	`if (z == NULL) return;`
`43`		`- if (S_size)`
	`43`	`+ if (z->S)`
`44`	`44`	`{`
`45`	`45`	`int i;`
`46`	`46`	`for (i = 0; i < S_size; i++)`