On Mon, Feb 8, 2021 at 4:03 PM Nicolas Iooss <nicolas.iooss@xxxxxxx> wrote:
>
> On Fri, Feb 5, 2021 at 3:44 PM James Carter <jwcart2@xxxxxxxxx> wrote:
> >
> > From: James Carter <jwcart2@xxxxxxxxxxxxx>
> >
> > Nicolass Iooss reports:
> > OSS-Fuzz found an integer overflow when compiling the following
> > (empty) CIL policy:
> >
> > ;;*lms 2147483647 a
> > ; (empty line)
> >
> > Change hll_lineno to uint32_t which is the type of the field hll_line
> > in struct cil_tree_node where the line number will be stored eventually.
> > Read the line number into an unsigned long variable using strtoul()
> > instead of strtol(). On systems where ULONG_MAX > UINT32_MAX, return
> > an error if the value is larger than UINT32_MAX.
> >
> > Also change hll_expand to uint32_t, since its value will be either
> > 0 or 1 and there is no need for it to be signed.
> >
> > Reported-by: Nicolass Iooss <nicolas.iooss@xxxxxxx>
> > Signed-off-by: James Carter <jwcart2@xxxxxxxxx>
>
> Acked-by: Nicolas Iooss <nicolas.iooss@xxxxxxx>
>
This has been applied (with your name corrected)
Jim
> By the way this week I have infrequent access to the system I use to
> work on SELinux stuff, so I will not be able to review/test/apply
> patches until next week-end. So feel free to merge this without
> waiting for me.
>
> Thanks,
> Nicolas
>
> > ---
> > libsepol/cil/src/cil_parser.c | 33 +++++++++++++++++++++------------
> > 1 file changed, 21 insertions(+), 12 deletions(-)
> >
> > diff --git a/libsepol/cil/src/cil_parser.c b/libsepol/cil/src/cil_parser.c
> > index 0038eed6..a9306218 100644
> > --- a/libsepol/cil/src/cil_parser.c
> > +++ b/libsepol/cil/src/cil_parser.c
> > @@ -47,11 +47,11 @@ char *CIL_KEY_HLL_LMX;
> > char *CIL_KEY_HLL_LME;
> >
> > struct hll_info {
> > - int hll_lineno;
> > - int hll_expand;
> > + uint32_t hll_lineno;
> > + uint32_t hll_expand;
> > };
> >
> > -static void push_hll_info(struct cil_stack *stack, int hll_lineno, int hll_expand)
> > +static void push_hll_info(struct cil_stack *stack, uint32_t hll_lineno, uint32_t hll_expand)
> > {
> > struct hll_info *new = cil_malloc(sizeof(*new));
> >
> > @@ -61,7 +61,7 @@ static void push_hll_info(struct cil_stack *stack, int hll_lineno, int hll_expan
> > cil_stack_push(stack, CIL_NONE, new);
> > }
> >
> > -static void pop_hll_info(struct cil_stack *stack, int *hll_lineno, int *hll_expand)
> > +static void pop_hll_info(struct cil_stack *stack, uint32_t *hll_lineno, uint32_t *hll_expand)
> > {
> > struct cil_stack_item *curr = cil_stack_pop(stack);
> > struct cil_stack_item *prev = cil_stack_peek(stack);
> > @@ -70,8 +70,8 @@ static void pop_hll_info(struct cil_stack *stack, int *hll_lineno, int *hll_expa
> > free(curr->data);
> >
> > if (!prev) {
> > - *hll_lineno = -1;
> > - *hll_expand = -1;
> > + *hll_lineno = 0;
> > + *hll_expand = 0;
> > } else {
> > old = prev->data;
> > *hll_lineno = old->hll_lineno;
> > @@ -79,7 +79,7 @@ static void pop_hll_info(struct cil_stack *stack, int *hll_lineno, int *hll_expa
> > }
> > }
> >
> > -static void create_node(struct cil_tree_node **node, struct cil_tree_node *current, int line, int hll_line, void *value)
> > +static void create_node(struct cil_tree_node **node, struct cil_tree_node *current, uint32_t line, uint32_t hll_line, void *value)
> > {
> > cil_tree_node_init(node);
> > (*node)->parent = current;
> > @@ -99,13 +99,14 @@ static void insert_node(struct cil_tree_node *node, struct cil_tree_node *curren
> > current->cl_tail = node;
> > }
> >
> > -static int add_hll_linemark(struct cil_tree_node **current, int *hll_lineno, int *hll_expand, struct cil_stack *stack, char *path)
> > +static int add_hll_linemark(struct cil_tree_node **current, uint32_t *hll_lineno, uint32_t *hll_expand, struct cil_stack *stack, char *path)
> > {
> > char *hll_type;
> > struct cil_tree_node *node;
> > struct token tok;
> > char *hll_file;
> > char *end = NULL;
> > + unsigned long val;
> >
> > cil_lexer_next(&tok);
> > hll_type = cil_strpool_add(tok.value);
> > @@ -141,11 +142,19 @@ static int add_hll_linemark(struct cil_tree_node **current, int *hll_lineno, int
> > cil_log(CIL_ERR, "Invalid line mark syntax\n");
> > goto exit;
> > }
> > - *hll_lineno = strtol(tok.value, &end, 10);
> > +
> > + val = strtoul(tok.value, &end, 10);
> > if (errno == ERANGE || *end != '\0') {
> > cil_log(CIL_ERR, "Problem parsing line number for line mark\n");
> > goto exit;
> > }
> > +#if ULONG_MAX > UINT32_MAX
> > + if (val > UINT32_MAX) {
> > + cil_log(CIL_ERR, "Line mark line number > UINT32_MAX\n");
> > + goto exit;
> > + }
> > +#endif
> > + *hll_lineno = val;
> >
> > push_hll_info(stack, *hll_lineno, *hll_expand);
> >
> > @@ -175,7 +184,7 @@ static int add_hll_linemark(struct cil_tree_node **current, int *hll_lineno, int
> > return SEPOL_OK;
> >
> > exit:
> > - cil_log(CIL_ERR, "Problem with high-level line mark at line %d of %s\n", tok.line, path);
> > + cil_log(CIL_ERR, "Problem with high-level line mark at line %u of %s\n", tok.line, path);
> > return SEPOL_ERR;
> > }
> >
> > @@ -207,8 +216,8 @@ int cil_parser(const char *_path, char *buffer, uint32_t size, struct cil_tree *
> > struct cil_tree_node *current = NULL;
> > char *path = cil_strpool_add(_path);
> > struct cil_stack *stack;
> > - int hll_lineno = -1;
> > - int hll_expand = -1;
> > + uint32_t hll_lineno = 0;
> > + uint32_t hll_expand = 0;
> > struct token tok;
> > int rc = SEPOL_OK;
> >
> > --
> > 2.26.2
> >
>
