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authorJann Horn <jannh@google.com>2019-05-28 17:32:26 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-25 11:36:51 +0800
commit4758984fa3ba0b1ac39687750e74ca0350ada753 (patch)
parentfadee027bf8fa90f3057a98a89871cbe8dd4adf5 (diff)
apparmor: enforce nullbyte at end of tag string
commit 8404d7a674c49278607d19726e0acc0cae299357 upstream. A packed AppArmor policy contains null-terminated tag strings that are read by unpack_nameX(). However, unpack_nameX() uses string functions on them without ensuring that they are actually null-terminated, potentially leading to out-of-bounds accesses. Make sure that the tag string is null-terminated before passing it to strcmp(). Cc: stable@vger.kernel.org Fixes: 736ec752d95e ("AppArmor: policy routines for loading and unpacking policy") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index 4ede87c30f8b..2cef8d4404cc 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -259,7 +259,7 @@ static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
char *tag = NULL;
size_t size = unpack_u16_chunk(e, &tag);
/* if a name is specified it must match. otherwise skip tag */
- if (name && (!size || strcmp(name, tag)))
+ if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag)))
goto fail;
} else if (name) {
/* if a name is specified and there is no name tag fail */