Merge branch 'update-null-pointer-handling-in-generated-code'

Thaison Phan says:

====================
update NULL pointer handling in generated code

This series fixes potential NULL pointer dereferences in YNL-generated C
code during dump list freeing and memory allocation in parsing getters.
====================

Link: https://patch.msgid.link/20260807171500.7188-1-thaisonphan@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 27 insertions, 8 deletions

diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py
index cdc3646f2642..2b3483db1b60 100755
--- a/tools/net/ynl/pyynl/ynl_gen_c.py
+++ b/tools/net/ynl/pyynl/ynl_gen_c.py
@@ -526,8 +526,10 @@ class TypeString(Type):
 
     def _attr_get(self, ri, var):
         len_mem = var + '->_len.' + self.c_name
-        return [f"{len_mem} = len;",
-                f"{var}->{self.c_name} = malloc(len + 1);",
+        return [f"{var}->{self.c_name} = malloc(len + 1);",
+                f"if (!{var}->{self.c_name})",
+                "return YNL_PARSE_CB_ERROR;",
+                f"{len_mem} = len;",
                 f"memcpy({var}->{self.c_name}, ynl_attr_get_str(attr), len);",
                 f"{var}->{self.c_name}[len] = 0;"], \
                ['len = strnlen(ynl_attr_get_str(attr), ynl_attr_data_len(attr));'], \
@@ -582,8 +584,10 @@ class TypeBinary(Type):
 
     def _attr_get(self, ri, var):
         len_mem = var + '->_len.' + self.c_name
-        return [f"{len_mem} = len;",
-                f"{var}->{self.c_name} = malloc(len);",
+        return [f"{var}->{self.c_name} = malloc(len);",
+                f"if (!{var}->{self.c_name})",
+                "return YNL_PARSE_CB_ERROR;",
+                f"{len_mem} = len;",
                 f"memcpy({var}->{self.c_name}, ynl_attr_data(attr), len);"], \
                ['len = ynl_attr_data_len(attr);'], \
                ['unsigned int len;']
@@ -601,11 +605,13 @@ class TypeBinaryStruct(TypeBinary):
     def _attr_get(self, ri, var):
         struct_sz = 'sizeof(struct ' + c_lower(self.get("struct")) + ')'
         len_mem = var + '->_' + self.presence_type() + '.' + self.c_name
-        return [f"{len_mem} = len;",
-                f"if (len < {struct_sz})",
+        return [f"if (len < {struct_sz})",
                 f"{var}->{self.c_name} = calloc(1, {struct_sz});",
                 "else",
                 f"{var}->{self.c_name} = malloc(len);",
+                f"if (!{var}->{self.c_name})",
+                "return YNL_PARSE_CB_ERROR;",
+                f"{len_mem} = len;",
                 f"memcpy({var}->{self.c_name}, ynl_attr_data(attr), len);"], \
                ['len = ynl_attr_data_len(attr);'], \
                ['unsigned int len;']
@@ -631,9 +637,11 @@ class TypeBinaryScalarArray(TypeBinary):
 
     def _attr_get(self, ri, var):
         len_mem = var + '->_count.' + self.c_name
-        return [f"{len_mem} = len / sizeof(__{self.get('sub-type')});",
-                f"len = {len_mem} * sizeof(__{self.get('sub-type')});",
+        return [f"len = (len / sizeof(__{self.get('sub-type')})) * sizeof(__{self.get('sub-type')});",
                 f"{var}->{self.c_name} = malloc(len);",
+                f"if (!{var}->{self.c_name})",
+                "return YNL_PARSE_CB_ERROR;",
+                f"{len_mem} = len / sizeof(__{self.get('sub-type')});",
                 f"memcpy({var}->{self.c_name}, ynl_attr_data(attr), len);"], \
                ['len = ynl_attr_data_len(attr);'], \
                ['unsigned int len;']
@@ -2227,6 +2235,8 @@ def _multi_parse(ri, struct, init_lines, local_vars):
 
         ri.cw.block_start(line=f"if (n_{aspec.c_name})")
         ri.cw.p(f"dst->{aspec.c_name} = calloc(n_{aspec.c_name}, sizeof(*dst->{aspec.c_name}));")
+        ri.cw.p(f"if (!dst->{aspec.c_name})")
+        ri.cw.p("return YNL_PARSE_CB_ERROR;")
         ri.cw.p(f"dst->_count.{aspec.c_name} = n_{aspec.c_name};")
         ri.cw.p('i = 0;')
         if 'nested-attributes' in aspec:
@@ -2252,6 +2262,8 @@ def _multi_parse(ri, struct, init_lines, local_vars):
         aspec = struct[arg]
         ri.cw.block_start(line=f"if (n_{aspec.c_name})")
         ri.cw.p(f"dst->{aspec.c_name} = calloc(n_{aspec.c_name}, sizeof(*dst->{aspec.c_name}));")
+        ri.cw.p(f"if (!dst->{aspec.c_name})")
+        ri.cw.p("return YNL_PARSE_CB_ERROR;")
         ri.cw.p(f"dst->_count.{aspec.c_name} = n_{aspec.c_name};")
         ri.cw.p('i = 0;')
         if 'nested-attributes' in aspec:
@@ -2275,6 +2287,8 @@ def _multi_parse(ri, struct, init_lines, local_vars):
             ri.cw.nl()
             ri.cw.p('len = strnlen(ynl_attr_get_str(attr), ynl_attr_data_len(attr));')
             ri.cw.p(f'dst->{aspec.c_name}[i] = malloc(sizeof(struct ynl_string) + len + 1);')
+            ri.cw.p(f"if (!dst->{aspec.c_name}[i])")
+            ri.cw.p("return YNL_PARSE_CB_ERROR;")
             ri.cw.p(f"dst->{aspec.c_name}[i]->len = len;")
             ri.cw.p(f"memcpy(dst->{aspec.c_name}[i]->str, ynl_attr_get_str(attr), len);")
             ri.cw.p(f"dst->{aspec.c_name}[i]->str[len] = 0;")
@@ -2434,6 +2448,8 @@ def print_req(ri):
 
     if 'reply' in ri.op[ri.op_mode]:
         ri.cw.p('rsp = calloc(1, sizeof(*rsp));')
+        ri.cw.p('if (!rsp)')
+        ri.cw.p(f'return {ret_err};')
         ri.cw.p('yrs.yarg.data = rsp;')
         ri.cw.p(f"yrs.cb = {op_prefix(ri, 'reply')}_parse;")
         if ri.op.value is not None:
@@ -2747,6 +2763,9 @@ def print_dump_type_free(ri):
     ri.cw.block_start()
     ri.cw.p(f"{sub_type} *next = rsp;")
     ri.cw.nl()
+    ri.cw.p('if (!next)')
+    ri.cw.p('return;')
+    ri.cw.nl()
     ri.cw.block_start(line='while ((void *)next != YNL_LIST_END)')
     _free_type_members_iter(ri, ri.struct['reply'])
     ri.cw.p('rsp = next;')