[PATCH 1/3] libsepol/cil: Properly check parse tree when printing error messages

[PATCH 1/3] libsepol/cil: Properly check parse tree when printing error messages

[James Carter]

The function cil_tree_get_next_path() does not check whether the
parse tree node that stores the high-level language file path of a
src_info rule actually exists before trying to read the path. This
can result in a NULL dereference.

Check that all of the parse tree nodes of a src_info rule exist
before reading the data from them.

This bug was found by the secilc-fuzzer.

Signed-off-by: James Carter <jwcart2@gmail.com>
---
 libsepol/cil/src/cil_tree.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libsepol/cil/src/cil_tree.c b/libsepol/cil/src/cil_tree.c
index 75293005..e70722ec 100644
--- a/libsepol/cil/src/cil_tree.c
+++ b/libsepol/cil/src/cil_tree.c
@@ -62,7 +62,10 @@ struct cil_tree_node *cil_tree_get_next_path(struct cil_tree_node *node, char **
 
 	while (node) {
 		if (node->flavor == CIL_NODE && node->data == NULL) {
-			if (node->cl_head->data == CIL_KEY_SRC_INFO && node->cl_head->next != NULL && node->cl_head->next->next != NULL) {
+			if (node->cl_head && node->cl_head->data == CIL_KEY_SRC_INFO) {
+				if (!node->cl_head->next || !node->cl_head->next->next || !node->cl_head->next->next->next) {
+					goto exit;
+				}
 				/* Parse Tree */
 				*info_kind = node->cl_head->next->data;
 				rc = cil_string_to_uint32(node->cl_head->next->next->data, hll_line, 10);
-- 
2.31.1

[PATCH 2/3] libsepol/cil: Reset expandtypeattribute rules when resetting AST

[James Carter]

A list is created to store type attribute datums when resolving an
expandtypeattribute rule and that list needs to be destroyed if the
AST is reset or a memory leak will occur.

Destroy the list storing type attributes datums when resetting
expandtypeattribute rules.

This bug was found by the secilc-fuzzer.

Signed-off-by: James Carter <jwcart2@gmail.com>
---
 libsepol/cil/src/cil_reset_ast.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/libsepol/cil/src/cil_reset_ast.c b/libsepol/cil/src/cil_reset_ast.c
index 6d1d2da7..0ba075c8 100644
--- a/libsepol/cil/src/cil_reset_ast.c
+++ b/libsepol/cil/src/cil_reset_ast.c
@@ -208,6 +208,11 @@ static void cil_reset_typeattributeset(struct cil_typeattributeset *tas)
 	cil_list_destroy(&tas->datum_expr, CIL_FALSE);
 }
 
+static void cil_reset_expandtypeattribute(struct cil_expandtypeattribute *expandattr)
+{
+	cil_list_destroy(&expandattr->attr_datums, CIL_FALSE);
+}
+
 static void cil_reset_avrule(struct cil_avrule *rule)
 {
 	cil_reset_classperms_list(rule->perms.classperms);
@@ -531,6 +536,9 @@ int __cil_reset_node(struct cil_tree_node *node,  __attribute__((unused)) uint32
 	case CIL_TYPEATTRIBUTESET:
 		cil_reset_typeattributeset(node->data);
 		break;
+	case CIL_EXPANDTYPEATTRIBUTE:
+		cil_reset_expandtypeattribute(node->data);
+		break;
 	case CIL_RANGETRANSITION:
 		cil_reset_rangetransition(node->data);
 		break;
@@ -630,7 +638,6 @@ int __cil_reset_node(struct cil_tree_node *node,  __attribute__((unused)) uint32
 	case CIL_CLASSORDER:
 	case CIL_CATORDER:
 	case CIL_SENSITIVITYORDER:
-	case CIL_EXPANDTYPEATTRIBUTE:
 		break; /* Nothing to reset */
 	default:
 		break;
-- 
2.31.1

[PATCH 3/3] libsepol/cil: Properly check for parameter when inserting name

[James Carter]

File names for typetransition rules are stored in their own datums.
This allows them to be passed as a parameter, but there needs to be
a check in __cil_insert_name() so that parameter names are not
mistaken for file name strings. This check did not verify that a
matching parameter name had the flavor of CIL_NAME.

Check that the parameter flavor is CIL_NAME and that the paramter
name matches the file name to be stored in the datum.

This bug was found by the secilc-fuzzer.

Signed-off-by: James Carter <jwcart2@gmail.com>
---
 libsepol/cil/src/cil_resolve_ast.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libsepol/cil/src/cil_resolve_ast.c b/libsepol/cil/src/cil_resolve_ast.c
index 18007324..a4de1c75 100644
--- a/libsepol/cil/src/cil_resolve_ast.c
+++ b/libsepol/cil/src/cil_resolve_ast.c
@@ -87,7 +87,8 @@ static struct cil_name * __cil_insert_name(struct cil_db *db, hashtab_key_t key,
 	if (macro != NULL && macro->params != NULL) {
 		struct cil_list_item *item;
 		cil_list_for_each(item, macro->params) {
-			if (((struct cil_param*)item->data)->str == key) {
+			struct cil_param *param = item->data;
+			if (param->flavor == CIL_NAME && param->str == key) {
 				return NULL;
 			}
 		}
-- 
2.31.1

Re: [PATCH 1/3] libsepol/cil: Properly check parse tree when printing error messages

[Nicolas Iooss]

On Fri, Aug 27, 2021 at 4:20 PM James Carter <jwcart2@gmail.com> wrote:
>
> The function cil_tree_get_next_path() does not check whether the
> parse tree node that stores the high-level language file path of a
> src_info rule actually exists before trying to read the path. This
> can result in a NULL dereference.
>
> Check that all of the parse tree nodes of a src_info rule exist
> before reading the data from them.
>
> This bug was found by the secilc-fuzzer.
>
> Signed-off-by: James Carter <jwcart2@gmail.com>

For the 3 patches:

Acked-by: Nicolas Iooss <nicolas.iooss@m4x.org>

Thanks,
Nicolas

> ---
>  libsepol/cil/src/cil_tree.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/libsepol/cil/src/cil_tree.c b/libsepol/cil/src/cil_tree.c
> index 75293005..e70722ec 100644
> --- a/libsepol/cil/src/cil_tree.c
> +++ b/libsepol/cil/src/cil_tree.c
> @@ -62,7 +62,10 @@ struct cil_tree_node *cil_tree_get_next_path(struct cil_tree_node *node, char **
>
>         while (node) {
>                 if (node->flavor == CIL_NODE && node->data == NULL) {
> -                       if (node->cl_head->data == CIL_KEY_SRC_INFO && node->cl_head->next != NULL && node->cl_head->next->next != NULL) {
> +                       if (node->cl_head && node->cl_head->data == CIL_KEY_SRC_INFO) {
> +                               if (!node->cl_head->next || !node->cl_head->next->next || !node->cl_head->next->next->next) {
> +                                       goto exit;
> +                               }
>                                 /* Parse Tree */
>                                 *info_kind = node->cl_head->next->data;
>                                 rc = cil_string_to_uint32(node->cl_head->next->next->data, hll_line, 10);
> --
> 2.31.1
>

Re: [PATCH 1/3] libsepol/cil: Properly check parse tree when printing error messages

[James Carter]

On Wed, Sep 1, 2021 at 3:22 PM Nicolas Iooss <nicolas.iooss@m4x.org> wrote:
>
> On Fri, Aug 27, 2021 at 4:20 PM James Carter <jwcart2@gmail.com> wrote:
> >
> > The function cil_tree_get_next_path() does not check whether the
> > parse tree node that stores the high-level language file path of a
> > src_info rule actually exists before trying to read the path. This
> > can result in a NULL dereference.
> >
> > Check that all of the parse tree nodes of a src_info rule exist
> > before reading the data from them.
> >
> > This bug was found by the secilc-fuzzer.
> >
> > Signed-off-by: James Carter <jwcart2@gmail.com>
>
> For the 3 patches:
>
> Acked-by: Nicolas Iooss <nicolas.iooss@m4x.org>
>

This series has been merged.
Thanks,
Jim

> Thanks,
> Nicolas
>
> > ---
> >  libsepol/cil/src/cil_tree.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/libsepol/cil/src/cil_tree.c b/libsepol/cil/src/cil_tree.c
> > index 75293005..e70722ec 100644
> > --- a/libsepol/cil/src/cil_tree.c
> > +++ b/libsepol/cil/src/cil_tree.c
> > @@ -62,7 +62,10 @@ struct cil_tree_node *cil_tree_get_next_path(struct cil_tree_node *node, char **
> >
> >         while (node) {
> >                 if (node->flavor == CIL_NODE && node->data == NULL) {
> > -                       if (node->cl_head->data == CIL_KEY_SRC_INFO && node->cl_head->next != NULL && node->cl_head->next->next != NULL) {
> > +                       if (node->cl_head && node->cl_head->data == CIL_KEY_SRC_INFO) {
> > +                               if (!node->cl_head->next || !node->cl_head->next->next || !node->cl_head->next->next->next) {
> > +                                       goto exit;
> > +                               }
> >                                 /* Parse Tree */
> >                                 *info_kind = node->cl_head->next->data;
> >                                 rc = cil_string_to_uint32(node->cl_head->next->next->data, hll_line, 10);
> > --
> > 2.31.1
> >
>