2023-07-06 13:28:24

by Christian Göttsche

Subject: [RFC PATCH 11/20] selinux: avc: avoid implicit conversions

Use a consistent type of u32 for sequence numbers.

Use a non-negative and input parameter matching type for the hash
result.

Signed-off-by: Christian Göttsche <[email protected]>
---
security/selinux/avc.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 1074db66e5ff..cd55479cce25 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -122,7 +122,7 @@ static struct kmem_cache *avc_xperms_data_cachep __ro_after_init;
static struct kmem_cache *avc_xperms_decision_cachep __ro_after_init;
static struct kmem_cache *avc_xperms_cachep __ro_after_init;

-static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
+static inline u32 avc_hash(u32 ssid, u32 tsid, u16 tclass)
{
return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1);
}
@@ -523,7 +523,7 @@ static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tcl
static inline struct avc_node *avc_search_node(u32 ssid, u32 tsid, u16 tclass)
{
struct avc_node *node, *ret = NULL;
- int hvalue;
+ u32 hvalue;
struct hlist_head *head;

hvalue = avc_hash(ssid, tsid, tclass);
@@ -566,7 +566,7 @@ static struct avc_node *avc_lookup(u32 ssid, u32 tsid, u16 tclass)
return NULL;
}

-static int avc_latest_notif_update(int seqno, int is_insert)
+static int avc_latest_notif_update(u32 seqno, int is_insert)
{
int ret = 0;
static DEFINE_SPINLOCK(notif_lock);
@@ -609,7 +609,7 @@ static void avc_insert(u32 ssid, u32 tsid, u16 tclass,
struct av_decision *avd, struct avc_xperms_node *xp_node)
{
struct avc_node *pos, *node = NULL;
- int hvalue;
+ u32 hvalue;
unsigned long flag;
spinlock_t *lock;
struct hlist_head *head;
@@ -654,9 +654,9 @@ static void avc_audit_pre_callback(struct audit_buffer *ab, void *a)
{
struct common_audit_data *ad = a;
struct selinux_audit_data *sad = ad->selinux_audit_data;
- u32 av = sad->audited;
+ u32 av = sad->audited, perm;
const char *const *perms;
- int i, perm;
+ u32 i;

audit_log_format(ab, "avc: %s ", sad->denied ? "denied" : "granted");

@@ -833,7 +833,8 @@ static int avc_update_node(u32 event, u32 perms, u8 driver, u8 xperm, u32 ssid,
struct extended_perms_decision *xpd,
u32 flags)
{
- int hvalue, rc = 0;
+ u32 hvalue;
+ int rc = 0;
unsigned long flag;
struct avc_node *pos, *node, *orig = NULL;
struct hlist_head *head;
--
2.40.1

2023-07-18 22:03:16

by Paul Moore

Subject: Re: [PATCH RFC 11/20] selinux: avc: avoid implicit conversions

On Jul 6, 2023 =?UTF-8?q?Christian=20G=C3=B6ttsche?= <[email protected]> wrote:
>
> Use a consistent type of u32 for sequence numbers.
>
> Use a non-negative and input parameter matching type for the hash
> result.
>
> Signed-off-by: Christian Göttsche <[email protected]>
> ---
> security/selinux/avc.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)

...

> diff --git a/security/selinux/avc.c b/security/selinux/avc.c
> index 1074db66e5ff..cd55479cce25 100644
> --- a/security/selinux/avc.c
> +++ b/security/selinux/avc.c
> @@ -654,9 +654,9 @@ static void avc_audit_pre_callback(struct audit_buffer *ab, void *a)
> {
> struct common_audit_data *ad = a;
> struct selinux_audit_data *sad = ad->selinux_audit_data;
> - u32 av = sad->audited;
> + u32 av = sad->audited, perm;
> const char *const *perms;
> - int i, perm;
> + u32 i;

Technically the perm type change doesn't fit with the description, but
it's minor enough that it shouldn't be an issue.

Merged into selinux/next.

> audit_log_format(ab, "avc: %s ", sad->denied ? "denied" : "granted");
>
> @@ -833,7 +833,8 @@ static int avc_update_node(u32 event, u32 perms, u8 driver, u8 xperm, u32 ssid,
> struct extended_perms_decision *xpd,
> u32 flags)
> {
> - int hvalue, rc = 0;
> + u32 hvalue;
> + int rc = 0;
> unsigned long flag;
> struct avc_node *pos, *node, *orig = NULL;
> struct hlist_head *head;
> --
> 2.40.1

--
paul-moore.com