[PATCH 3.10 117/268] apparmor: add missing id bounds check on dfa verification

Willy Tarreau
2017-06-19T19:02:26Z

From: John Johansen <john.johansen@canonical.com>

commit 15756178c6a65b261a080e21af4766f59cafc112 upstream.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
security/apparmor/include/match.h | 1 +
security/apparmor/match.c | 2 ++
2 files changed, 3 insertions(+)

diff --git a/security/apparmor/include/match.h b/security/apparmor/include/match.h
index 775843e..b5029c7 100644
--- a/security/apparmor/include/match.h
+++ b/security/apparmor/include/match.h
@@ -57,6 +57,7 @@ struct table_set_header {
#define YYTD_ID_ACCEPT2 6
#define YYTD_ID_NXT 7
#define YYTD_ID_TSIZE 8
+#define YYTD_ID_MAX 8

#define YYTD_DATA8 1
#define YYTD_DATA16 2
diff --git a/security/apparmor/match.c b/security/apparmor/match.c
index 90971a8..630f325 100644
--- a/security/apparmor/match.c
+++ b/security/apparmor/match.c
@@ -45,6 +45,8 @@ static struct table_header *unpack_table(char *blob, size_t bsize)
* it every time we use td_id as an index
*/
th.td_id = be16_to_cpu(*(u16 *) (blob)) - 1;
+ if (th.td_id > YYTD_ID_MAX)
+ goto out;
th.td_flags = be16_to_cpu(*(u16 *) (blob + 2));
th.td_lolen = be32_to_cpu(*(u32 *) (blob + 8));
blob += sizeof(struct table_header);
--
2.8.0.rc2.1.gbe9624a