[PATCH v2] checkpolicy: fix the leak memory when uses xperms

[liwugang <liwugang@xxxxxxx>]

In the define_te_avtab_ioctl function:
1. the parameter avrule_template has been copied to
new elements which added to avrule list through
the function avrule_cpy, so it should free avrule_template.
2. And for rangelist, it does not free the allocated memory.

The memory leak can by found by using memory sanitizer:
=================================================================
==20021==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 10336 byte(s) in 76 object(s) allocated from:
    #0 0x7f8f96d9cb50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
    #1 0x55c2e9447fb3 in define_te_avtab_xperms_helper /mnt/sources/tools/selinux/checkpolicy/policy_define.c:2046
    #2 0x55c2e944a6ca in define_te_avtab_extended_perms /mnt/sources/tools/selinux/checkpolicy/policy_define.c:2479
    #3 0x55c2e943126b in yyparse /mnt/sources/tools/selinux/checkpolicy/policy_parse.y:494
    #4 0x55c2e9440221 in read_source_policy /mnt/sources/tools/selinux/checkpolicy/parse_util.c:64
    #5 0x55c2e945a3df in main /mnt/sources/tools/selinux/checkpolicy/checkpolicy.c:619
    #6 0x7f8f968eeb96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)

Direct leak of 240 byte(s) in 15 object(s) allocated from:
    #0 0x7f8f96d9cb50 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xdeb50)
    #1 0x55c2e9446cd9 in avrule_sort_ioctls /mnt/sources/tools/selinux/checkpolicy/policy_define.c:1846
    #2 0x55c2e9447d8f in avrule_ioctl_ranges /mnt/sources/tools/selinux/checkpolicy/policy_define.c:2020
    #3 0x55c2e944a0de in define_te_avtab_ioctl /mnt/sources/tools/selinux/checkpolicy/policy_define.c:2409
    #4 0x55c2e944a744 in define_te_avtab_extended_perms /mnt/sources/tools/selinux/checkpolicy/policy_define.c:2485
    #5 0x55c2e94312bf in yyparse /mnt/sources/tools/selinux/checkpolicy/policy_parse.y:503
    #6 0x55c2e9440221 in read_source_policy /mnt/sources/tools/selinux/checkpolicy/parse_util.c:64
    #7 0x55c2e945a3df in main /mnt/sources/tools/selinux/checkpolicy/checkpolicy.c:619
    #8 0x7f8f968eeb96 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b96)

Tested-By: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
Signed-off-by: liwugang <liwugang@xxxxxxx>
---
 checkpolicy/policy_define.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/checkpolicy/policy_define.c b/checkpolicy/policy_define.c
index 16234f31..52105d3a 100644
--- a/checkpolicy/policy_define.c
+++ b/checkpolicy/policy_define.c
@@ -2400,7 +2400,7 @@ int avrule_cpy(avrule_t *dest, avrule_t *src)
 int define_te_avtab_ioctl(avrule_t *avrule_template)
 {
 	avrule_t *avrule;
-	struct av_ioctl_range_list *rangelist;
+	struct av_ioctl_range_list *rangelist, *r;
 	av_extended_perms_t *complete_driver, *partial_driver, *xperms;
 	unsigned int i;
 
@@ -2458,6 +2458,12 @@ done:
 	if (partial_driver)
 		free(partial_driver);
 
+	while (rangelist != NULL) {
+		r = rangelist;
+		rangelist = rangelist->next;
+		free(r);
+	}
+
 	return 0;
 }
 
@@ -2484,6 +2490,8 @@ int define_te_avtab_extended_perms(int which)
 		free(id);
 		if (define_te_avtab_ioctl(avrule_template))
 			return -1;
+		avrule_destroy(avrule_template);
+		free(avrule_template);
 	} else {
 		yyerror("only ioctl extended permissions are supported");
 		free(id);
-- 
2.30.2