[PATCH] opcodes: Fix null pointer dereference vulnerability in pv_dup function

[pengxu@kylinos.cn]

   In opcodes/opc2c.c file, in the pv_dup() function, directly calling memcpy after malloc poses potential memory safety issues, with the following specific defects:

No check for malloc return value:
malloc may fail and return NULL. Calling memcpy on a NULL pointer results in undefined behavior (typically a segmentation fault).
A check for rv == NULL should be added：
	if (rv == NULL)
	  return NULL; 

---
 opcodes/opc2c.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/opcodes/opc2c.c b/opcodes/opc2c.c
index 5e5fba67add..f66877fbcc4 100644
--- a/opcodes/opc2c.c
+++ b/opcodes/opc2c.c
@@ -462,6 +462,8 @@ pv_dup (char * p, char * ep)
 {
   int n = ep - p;
   char *rv = (char *) malloc (n + 1);
+  if (rv == NULL)
+    return NULL;
 
   memcpy (rv, p, n);
   rv[n] = 0;
-- 
2.25.1