Re: [PATCH] crypto: resource release functions ought to check forNULL (crypto_free_tfm)

From: Jesper Juhl
Date: Mon Apr 18 2005 - 10:27:09 EST

On Mon, 18 Apr 2005, Herbert Xu wrote:

> On Fri, Apr 15, 2005 at 01:15:58AM +0200, Jesper Juhl wrote:
> >
> > As far as I'm aware there's a general concensus that functions that are
> > responsible for freeing resources should be able to cope with being passed
> > a NULL pointer. This makes sense as it removes the need for all callers to
>
> In general I'd only do this when most of the callers are doing the
> NULL check. As that seems to be the case here, I agree with your
> change. I've applied it to my tree.
>
Great, thank you.

Next step is to then clean up the callers of crypto_free_tfm so they no
longer do the redundant NULL check. Below is a patch to do that.


Signed-off-by: Jesper Juhl <juhl
---

drivers/net/wireless/airo.c | 3 --
drivers/net/wireless/hostap/hostap_crypt_ccmp.c | 5 +---
drivers/net/wireless/hostap/hostap_crypt_tkip.c | 10 +++-----
drivers/net/wireless/hostap/hostap_crypt_wep.c | 5 +---
net/ieee80211/ieee80211_crypt_ccmp.c | 5 +---
net/ieee80211/ieee80211_crypt_tkip.c | 10 +++-----
net/ieee80211/ieee80211_crypt_wep.c | 5 +---
net/ipv4/ah4.c | 18 +++++----------
net/ipv4/esp4.c | 28 ++++++++++--------------
net/ipv4/ipcomp.c | 3 --
net/ipv6/addrconf.c | 6 +----
net/ipv6/ah6.c | 20 ++++++-----------
net/ipv6/esp6.c | 28 ++++++++++--------------
net/ipv6/ipcomp6.c | 3 --
net/sctp/endpointola.c | 3 --
net/sctp/socket.c | 3 --
net/sunrpc/auth_gss/gss_krb5_crypto.c | 3 --
net/sunrpc/auth_gss/gss_krb5_mech.c | 9 ++-----
net/sunrpc/auth_gss/gss_spkm3_mech.c | 12 +++-------
19 files changed, 69 insertions(+), 110 deletions(-)


--- linux-2.6.12-rc2-mm3-orig/drivers/net/wireless/airo.c 2005-04-11 21:20:48.000000000 +0200
+++ linux-2.6.12-rc2-mm3/drivers/net/wireless/airo.c 2005-04-18 16:57:57.000000000 +0200
@@ -2406,8 +2406,7 @@ void stop_airo_card( struct net_device *
}
}
#ifdef MICSUPPORT
- if (ai->tfm)
- crypto_free_tfm(ai->tfm);
+ crypto_free_tfm(ai->tfm);
#endif
del_airo_dev( dev );
free_netdev( dev );
--- linux-2.6.12-rc2-mm3-orig/drivers/net/wireless/hostap/hostap_crypt_ccmp.c 2005-04-11 21:20:48.000000000 +0200
+++ linux-2.6.12-rc2-mm3/drivers/net/wireless/hostap/hostap_crypt_ccmp.c 2005-04-18 16:58:36.000000000 +0200
@@ -109,8 +109,7 @@ static void * hostap_ccmp_init(int key_i

fail:
if (priv) {
- if (priv->tfm)
- crypto_free_tfm(priv->tfm);
+ crypto_free_tfm(priv->tfm);
kfree(priv);
}
module_put(THIS_MODULE);
@@ -121,7 +120,7 @@ fail:
static void hostap_ccmp_deinit(void *priv)
{
struct hostap_ccmp_data *_priv = priv;
- if (_priv && _priv->tfm)
+ if (_priv)
crypto_free_tfm(_priv->tfm);
kfree(priv);
module_put(THIS_MODULE);
--- linux-2.6.12-rc2-mm3-orig/drivers/net/wireless/hostap/hostap_crypt_tkip.c 2005-04-11 21:20:48.000000000 +0200
+++ linux-2.6.12-rc2-mm3/drivers/net/wireless/hostap/hostap_crypt_tkip.c 2005-04-18 16:59:44.000000000 +0200
@@ -102,10 +102,8 @@ static void * hostap_tkip_init(int key_i

fail:
if (priv) {
- if (priv->tfm_michael)
- crypto_free_tfm(priv->tfm_michael);
- if (priv->tfm_arc4)
- crypto_free_tfm(priv->tfm_arc4);
+ crypto_free_tfm(priv->tfm_michael);
+ crypto_free_tfm(priv->tfm_arc4);
kfree(priv);
}
module_put(THIS_MODULE);
@@ -116,10 +114,10 @@ fail:
static void hostap_tkip_deinit(void *priv)
{
struct hostap_tkip_data *_priv = priv;
- if (_priv && _priv->tfm_michael)
+ if (_priv) {
crypto_free_tfm(_priv->tfm_michael);
- if (_priv && _priv->tfm_arc4)
crypto_free_tfm(_priv->tfm_arc4);
+ }
kfree(priv);
module_put(THIS_MODULE);
}
--- linux-2.6.12-rc2-mm3-orig/drivers/net/wireless/hostap/hostap_crypt_wep.c 2005-04-11 21:20:48.000000000 +0200
+++ linux-2.6.12-rc2-mm3/drivers/net/wireless/hostap/hostap_crypt_wep.c 2005-04-18 17:00:28.000000000 +0200
@@ -69,8 +69,7 @@ static void * prism2_wep_init(int keyidx

fail:
if (priv) {
- if (priv->tfm)
- crypto_free_tfm(priv->tfm);
+ crypto_free_tfm(priv->tfm);
kfree(priv);
}
module_put(THIS_MODULE);
@@ -81,7 +80,7 @@ fail:
static void prism2_wep_deinit(void *priv)
{
struct prism2_wep_data *_priv = priv;
- if (_priv && _priv->tfm)
+ if (_priv)
crypto_free_tfm(_priv->tfm);
kfree(priv);
module_put(THIS_MODULE);
--- linux-2.6.12-rc2-mm3-orig/net/ieee80211/ieee80211_crypt_ccmp.c 2005-04-11 21:20:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ieee80211/ieee80211_crypt_ccmp.c 2005-04-18 17:01:27.000000000 +0200
@@ -96,8 +96,7 @@ static void * ieee80211_ccmp_init(int ke

fail:
if (priv) {
- if (priv->tfm)
- crypto_free_tfm(priv->tfm);
+ crypto_free_tfm(priv->tfm);
kfree(priv);
}

@@ -108,7 +107,7 @@ fail:
static void ieee80211_ccmp_deinit(void *priv)
{
struct ieee80211_ccmp_data *_priv = priv;
- if (_priv && _priv->tfm)
+ if (_priv)
crypto_free_tfm(_priv->tfm);
kfree(priv);
}
--- linux-2.6.12-rc2-mm3-orig/net/ieee80211/ieee80211_crypt_tkip.c 2005-04-11 21:20:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ieee80211/ieee80211_crypt_tkip.c 2005-04-18 17:01:58.000000000 +0200
@@ -90,10 +90,8 @@ static void * ieee80211_tkip_init(int ke

fail:
if (priv) {
- if (priv->tfm_michael)
- crypto_free_tfm(priv->tfm_michael);
- if (priv->tfm_arc4)
- crypto_free_tfm(priv->tfm_arc4);
+ crypto_free_tfm(priv->tfm_michael);
+ crypto_free_tfm(priv->tfm_arc4);
kfree(priv);
}

@@ -104,10 +102,10 @@ fail:
static void ieee80211_tkip_deinit(void *priv)
{
struct ieee80211_tkip_data *_priv = priv;
- if (_priv && _priv->tfm_michael)
+ if (_priv) {
crypto_free_tfm(_priv->tfm_michael);
- if (_priv && _priv->tfm_arc4)
crypto_free_tfm(_priv->tfm_arc4);
+ }
kfree(priv);
}

--- linux-2.6.12-rc2-mm3-orig/net/ieee80211/ieee80211_crypt_wep.c 2005-04-11 21:20:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ieee80211/ieee80211_crypt_wep.c 2005-04-18 17:02:24.000000000 +0200
@@ -64,8 +64,7 @@ static void * prism2_wep_init(int keyidx

fail:
if (priv) {
- if (priv->tfm)
- crypto_free_tfm(priv->tfm);
+ crypto_free_tfm(priv->tfm);
kfree(priv);
}
return NULL;
@@ -75,7 +74,7 @@ fail:
static void prism2_wep_deinit(void *priv)
{
struct prism2_wep_data *_priv = priv;
- if (_priv && _priv->tfm)
+ if (_priv)
crypto_free_tfm(_priv->tfm);
kfree(priv);
}
--- linux-2.6.12-rc2-mm3-orig/net/ipv4/ah4.c 2005-04-05 21:21:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ipv4/ah4.c 2005-04-18 17:03:36.000000000 +0200
@@ -263,10 +263,8 @@ static int ah_init_state(struct xfrm_sta

error:
if (ahp) {
- if (ahp->work_icv)
- kfree(ahp->work_icv);
- if (ahp->tfm)
- crypto_free_tfm(ahp->tfm);
+ kfree(ahp->work_icv);
+ crypto_free_tfm(ahp->tfm);
kfree(ahp);
}
return -EINVAL;
@@ -279,14 +277,10 @@ static void ah_destroy(struct xfrm_state
if (!ahp)
return;

- if (ahp->work_icv) {
- kfree(ahp->work_icv);
- ahp->work_icv = NULL;
- }
- if (ahp->tfm) {
- crypto_free_tfm(ahp->tfm);
- ahp->tfm = NULL;
- }
+ kfree(ahp->work_icv);
+ ahp->work_icv = NULL;
+ crypto_free_tfm(ahp->tfm);
+ ahp->tfm = NULL;
kfree(ahp);
}

--- linux-2.6.12-rc2-mm3-orig/net/ipv4/esp4.c 2005-04-05 21:21:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ipv4/esp4.c 2005-04-18 17:09:26.000000000 +0200
@@ -343,22 +343,18 @@ static void esp_destroy(struct xfrm_stat
if (!esp)
return;

- if (esp->conf.tfm) {
- crypto_free_tfm(esp->conf.tfm);
- esp->conf.tfm = NULL;
- }
- if (esp->conf.ivec) {
- kfree(esp->conf.ivec);
- esp->conf.ivec = NULL;
- }
- if (esp->auth.tfm) {
- crypto_free_tfm(esp->auth.tfm);
- esp->auth.tfm = NULL;
- }
- if (esp->auth.work_icv) {
- kfree(esp->auth.work_icv);
- esp->auth.work_icv = NULL;
- }
+ crypto_free_tfm(esp->conf.tfm);
+ esp->conf.tfm = NULL;
+
+ kfree(esp->conf.ivec);
+ esp->conf.ivec = NULL;
+
+ crypto_free_tfm(esp->auth.tfm);
+ esp->auth.tfm = NULL;
+
+ kfree(esp->auth.work_icv);
+ esp->auth.work_icv = NULL;
+
kfree(esp);
}

--- linux-2.6.12-rc2-mm3-orig/net/ipv4/ipcomp.c 2005-04-05 21:21:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ipv4/ipcomp.c 2005-04-18 17:09:42.000000000 +0200
@@ -350,8 +350,7 @@ static void ipcomp_free_tfms(struct cryp

for_each_cpu(cpu) {
struct crypto_tfm *tfm = *per_cpu_ptr(tfms, cpu);
- if (tfm)
- crypto_free_tfm(tfm);
+ crypto_free_tfm(tfm);
}
free_percpu(tfms);
}
--- linux-2.6.12-rc2-mm3-orig/net/ipv6/addrconf.c 2005-04-11 21:20:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ipv6/addrconf.c 2005-04-18 17:10:08.000000000 +0200
@@ -3604,10 +3604,8 @@ void __exit addrconf_cleanup(void)
rtnl_unlock();

#ifdef CONFIG_IPV6_PRIVACY
- if (likely(md5_tfm != NULL)) {
- crypto_free_tfm(md5_tfm);
- md5_tfm = NULL;
- }
+ crypto_free_tfm(md5_tfm);
+ md5_tfm = NULL;
#endif

#ifdef CONFIG_PROC_FS
--- linux-2.6.12-rc2-mm3-orig/net/ipv6/ah6.c 2005-04-05 21:21:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ipv6/ah6.c 2005-04-18 17:10:50.000000000 +0200
@@ -402,10 +402,8 @@ static int ah6_init_state(struct xfrm_st

error:
if (ahp) {
- if (ahp->work_icv)
- kfree(ahp->work_icv);
- if (ahp->tfm)
- crypto_free_tfm(ahp->tfm);
+ kfree(ahp->work_icv);
+ crypto_free_tfm(ahp->tfm);
kfree(ahp);
}
return -EINVAL;
@@ -418,14 +416,12 @@ static void ah6_destroy(struct xfrm_stat
if (!ahp)
return;

- if (ahp->work_icv) {
- kfree(ahp->work_icv);
- ahp->work_icv = NULL;
- }
- if (ahp->tfm) {
- crypto_free_tfm(ahp->tfm);
- ahp->tfm = NULL;
- }
+ kfree(ahp->work_icv);
+ ahp->work_icv = NULL;
+
+ crypto_free_tfm(ahp->tfm);
+ ahp->tfm = NULL;
+
kfree(ahp);
}

--- linux-2.6.12-rc2-mm3-orig/net/ipv6/esp6.c 2005-04-05 21:21:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ipv6/esp6.c 2005-04-18 17:11:29.000000000 +0200
@@ -277,22 +277,18 @@ static void esp6_destroy(struct xfrm_sta
if (!esp)
return;

- if (esp->conf.tfm) {
- crypto_free_tfm(esp->conf.tfm);
- esp->conf.tfm = NULL;
- }
- if (esp->conf.ivec) {
- kfree(esp->conf.ivec);
- esp->conf.ivec = NULL;
- }
- if (esp->auth.tfm) {
- crypto_free_tfm(esp->auth.tfm);
- esp->auth.tfm = NULL;
- }
- if (esp->auth.work_icv) {
- kfree(esp->auth.work_icv);
- esp->auth.work_icv = NULL;
- }
+ crypto_free_tfm(esp->conf.tfm);
+ esp->conf.tfm = NULL;
+
+ kfree(esp->conf.ivec);
+ esp->conf.ivec = NULL;
+
+ crypto_free_tfm(esp->auth.tfm);
+ esp->auth.tfm = NULL;
+
+ kfree(esp->auth.work_icv);
+ esp->auth.work_icv = NULL;
+
kfree(esp);
}

--- linux-2.6.12-rc2-mm3-orig/net/ipv6/ipcomp6.c 2005-04-05 21:21:57.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/ipv6/ipcomp6.c 2005-04-18 17:11:40.000000000 +0200
@@ -346,8 +346,7 @@ static void ipcomp6_free_tfms(struct cry

for_each_cpu(cpu) {
struct crypto_tfm *tfm = *per_cpu_ptr(tfms, cpu);
- if (tfm)
- crypto_free_tfm(tfm);
+ crypto_free_tfm(tfm);
}
free_percpu(tfms);
}
--- linux-2.6.12-rc2-mm3-orig/net/sctp/endpointola.c 2005-04-05 21:21:58.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/sctp/endpointola.c 2005-04-18 17:12:15.000000000 +0200
@@ -194,8 +194,7 @@ static void sctp_endpoint_destroy(struct
sctp_unhash_endpoint(ep);

/* Free up the HMAC transform. */
- if (sctp_sk(ep->base.sk)->hmac)
- sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);
+ sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);

/* Cleanup. */
sctp_inq_free(&ep->base.inqueue);
--- linux-2.6.12-rc2-mm3-orig/net/sctp/socket.c 2005-04-05 21:21:59.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/sctp/socket.c 2005-04-18 17:12:28.000000000 +0200
@@ -4005,8 +4005,7 @@ out:
sctp_release_sock(sk);
return err;
cleanup:
- if (tfm)
- sctp_crypto_free_tfm(tfm);
+ sctp_crypto_free_tfm(tfm);
goto out;
}

--- linux-2.6.12-rc2-mm3-orig/net/sunrpc/auth_gss/gss_krb5_crypto.c 2005-03-02 08:37:47.000000000 +0100
+++ linux-2.6.12-rc2-mm3/net/sunrpc/auth_gss/gss_krb5_crypto.c 2005-04-18 17:12:36.000000000 +0200
@@ -201,8 +201,7 @@ make_checksum(s32 cksumtype, char *heade
crypto_digest_final(tfm, cksum->data);
code = 0;
out:
- if (tfm)
- crypto_free_tfm(tfm);
+ crypto_free_tfm(tfm);
return code;
}

--- linux-2.6.12-rc2-mm3-orig/net/sunrpc/auth_gss/gss_krb5_mech.c 2005-04-05 21:21:59.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/sunrpc/auth_gss/gss_krb5_mech.c 2005-04-18 17:13:20.000000000 +0200
@@ -185,12 +185,9 @@ static void
gss_delete_sec_context_kerberos(void *internal_ctx) {
struct krb5_ctx *kctx = internal_ctx;

- if (kctx->seq)
- crypto_free_tfm(kctx->seq);
- if (kctx->enc)
- crypto_free_tfm(kctx->enc);
- if (kctx->mech_used.data)
- kfree(kctx->mech_used.data);
+ crypto_free_tfm(kctx->seq);
+ crypto_free_tfm(kctx->enc);
+ kfree(kctx->mech_used.data);
kfree(kctx);
}

--- linux-2.6.12-rc2-mm3-orig/net/sunrpc/auth_gss/gss_spkm3_mech.c 2005-04-05 21:21:59.000000000 +0200
+++ linux-2.6.12-rc2-mm3/net/sunrpc/auth_gss/gss_spkm3_mech.c 2005-04-18 17:13:45.000000000 +0200
@@ -214,14 +214,10 @@ static void
gss_delete_sec_context_spkm3(void *internal_ctx) {
struct spkm3_ctx *sctx = internal_ctx;

- if(sctx->derived_integ_key)
- crypto_free_tfm(sctx->derived_integ_key);
- if(sctx->derived_conf_key)
- crypto_free_tfm(sctx->derived_conf_key);
- if(sctx->share_key.data)
- kfree(sctx->share_key.data);
- if(sctx->mech_used.data)
- kfree(sctx->mech_used.data);
+ crypto_free_tfm(sctx->derived_integ_key);
+ crypto_free_tfm(sctx->derived_conf_key);
+ kfree(sctx->share_key.data);
+ kfree(sctx->mech_used.data);
kfree(sctx);
}



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