On Wed, Apr 02, 2014 at 10:29:15PM +0200, Jakub Hrozek wrote:
Hi,
please see the attached patch that fixes a use-after-free bug in the
SELinux provider.
Pair-Programmed-With: lslebodn(a)redhat.com
The patch solves the issue, but I think the issue was there in the first
place, because the 'order' string is somewhat hidden. I would suggest to
use a struct like
struct order_ctx {
const char *order;
char **order_array;
size_t order_count;
};
It might be a bit overkill for this small usage, but I think it makes
the intention and the relation between order and order_array more clear.
bye,
Sumit
From 538afda9760d0baae716b159e36da3c5edcaef29 Mon Sep 17 00:00:00
2001
From: Jakub Hrozek <jhrozek(a)redhat.com>
Date: Wed, 2 Apr 2014 22:11:59 +0200
Subject: [PATCH] IPA: Fix SELinux mapping order memory hierarchy
https://fedorahosted.org/sssd/ticket/2300
The list of SELinux mapping orders was allocated on tmp_ctx and parsed
into an array. The array itself was correctly allocated on mem_ctx but
its contents remained on tmp_ctx, leading to a use-after-free error.
This patch fixes the memory hierarchy so that both the array and its
contents are allocated on mem_ctx.
---
src/providers/ipa/ipa_selinux.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/src/providers/ipa/ipa_selinux.c b/src/providers/ipa/ipa_selinux.c
index 1fc0c68d0bdc7cc5131d61694db26a208c51d300..7c3ce45c606595b52b13beca749c1c9d93bd31f2
100644
--- a/src/providers/ipa/ipa_selinux.c
+++ b/src/providers/ipa/ipa_selinux.c
@@ -601,21 +601,15 @@ static errno_t create_order_array(TALLOC_CTX *mem_ctx, const char
*map_order,
goto done;
}
- order = talloc_strdup(tmp_ctx, map_order);
- if (order == NULL) {
- ret = ENOMEM;
- goto done;
- }
- len = strlen(order);
-
/* The "order" string contains one or more SELinux user records
* separated by $. Now we need to create an array of string from
* this one string. First find out how many elements in the array
* will be. This way only one alloc will be necessary for the array
*/
order_count = 1;
+ len = strlen(map_order);
for (i = 0; i < len; i++) {
- if (order[i] == '$') order_count++;
+ if (map_order[i] == '$') order_count++;
}
order_array = talloc_array(tmp_ctx, char *, order_count);
@@ -624,6 +618,12 @@ static errno_t create_order_array(TALLOC_CTX *mem_ctx, const char
*map_order,
goto done;
}
+ order = talloc_strdup(order_array, map_order);
+ if (order == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+
/* Now fill the array with pointers to the original string. Also
* use binary zeros to make multiple string out of the one.
*/
--
1.9.0
_______________________________________________
sssd-devel mailing list
sssd-devel(a)lists.fedorahosted.org
https://lists.fedorahosted.org/mailman/listinfo/sssd-devel