* pull request (net-next): ipsec-next 2020-12-12
@ 2020-12-12 8:57 Steffen Klassert
2020-12-12 8:57 ` [PATCH] xfrm: redact SA secret with lockdown confidentiality Steffen Klassert
2020-12-12 21:40 ` pull request (net-next): ipsec-next 2020-12-12 patchwork-bot+netdevbpf
0 siblings, 2 replies; 7+ messages in thread
From: Steffen Klassert @ 2020-12-12 8:57 UTC (permalink / raw)
To: David Miller, Jakub Kicinski; +Cc: Herbert Xu, Steffen Klassert, netdev
Just one patch this time:
1) Redact the SA keys with kernel lockdown confidentiality.
If enabled, no secret keys are sent to uuserspace.
From Antony Antony.
Please pull or let me know if there are problems.
Thanks!
The following changes since commit 8be33ecfc1ffd2da20cc29e957e4cb6eb99310cb:
net: skb_vlan_untag(): don't reset transport offset if set by GRO layer (2020-11-09 20:03:55 -0800)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next.git master
for you to fetch changes up to c7a5899eb26e2a4d516d53f65b6dd67be2228041:
xfrm: redact SA secret with lockdown confidentiality (2020-11-27 11:03:06 +0100)
----------------------------------------------------------------
Antony Antony (1):
xfrm: redact SA secret with lockdown confidentiality
include/linux/security.h | 1 +
net/xfrm/xfrm_user.c | 74 +++++++++++++++++++++++++++++++++++++++++++-----
security/security.c | 1 +
3 files changed, 69 insertions(+), 7 deletions(-)
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH] xfrm: redact SA secret with lockdown confidentiality
2020-12-12 8:57 pull request (net-next): ipsec-next 2020-12-12 Steffen Klassert
@ 2020-12-12 8:57 ` Steffen Klassert
2020-12-12 21:40 ` patchwork-bot+netdevbpf
2020-12-12 21:40 ` pull request (net-next): ipsec-next 2020-12-12 patchwork-bot+netdevbpf
1 sibling, 1 reply; 7+ messages in thread
From: Steffen Klassert @ 2020-12-12 8:57 UTC (permalink / raw)
To: David Miller, Jakub Kicinski; +Cc: Herbert Xu, Steffen Klassert, netdev
From: Antony Antony <antony.antony@secunet.com>
redact XFRM SA secret in the netlink response to xfrm_get_sa()
or dumpall sa.
Enable lockdown, confidentiality mode, at boot or at run time.
e.g. when enabled:
cat /sys/kernel/security/lockdown
none integrity [confidentiality]
ip xfrm state
src 172.16.1.200 dst 172.16.1.100
proto esp spi 0x00000002 reqid 2 mode tunnel
replay-window 0
aead rfc4106(gcm(aes)) 0x0000000000000000000000000000000000000000 96
note: the aead secret is redacted.
Redacting secret is also a FIPS 140-2 requirement.
v1->v2
- add size checks before memset calls
v2->v3
- replace spaces with tabs for consistency
v3->v4
- use kernel lockdown instead of a /proc setting
v4->v5
- remove kconfig option
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
include/linux/security.h | 1 +
net/xfrm/xfrm_user.c | 74 ++++++++++++++++++++++++++++++++++++----
security/security.c | 1 +
3 files changed, 69 insertions(+), 7 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index bc2725491560..1112a79a7dba 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -127,6 +127,7 @@ enum lockdown_reason {
LOCKDOWN_PERF,
LOCKDOWN_TRACEFS,
LOCKDOWN_XMON_RW,
+ LOCKDOWN_XFRM_SECRET,
LOCKDOWN_CONFIDENTIALITY_MAX,
};
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index d0c32a8fcc4a..0727ac853b55 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -848,21 +848,84 @@ static int copy_user_offload(struct xfrm_state_offload *xso, struct sk_buff *skb
return 0;
}
+static bool xfrm_redact(void)
+{
+ return IS_ENABLED(CONFIG_SECURITY) &&
+ security_locked_down(LOCKDOWN_XFRM_SECRET);
+}
+
static int copy_to_user_auth(struct xfrm_algo_auth *auth, struct sk_buff *skb)
{
struct xfrm_algo *algo;
+ struct xfrm_algo_auth *ap;
struct nlattr *nla;
+ bool redact_secret = xfrm_redact();
nla = nla_reserve(skb, XFRMA_ALG_AUTH,
sizeof(*algo) + (auth->alg_key_len + 7) / 8);
if (!nla)
return -EMSGSIZE;
-
algo = nla_data(nla);
strncpy(algo->alg_name, auth->alg_name, sizeof(algo->alg_name));
- memcpy(algo->alg_key, auth->alg_key, (auth->alg_key_len + 7) / 8);
+
+ if (redact_secret && auth->alg_key_len)
+ memset(algo->alg_key, 0, (auth->alg_key_len + 7) / 8);
+ else
+ memcpy(algo->alg_key, auth->alg_key,
+ (auth->alg_key_len + 7) / 8);
algo->alg_key_len = auth->alg_key_len;
+ nla = nla_reserve(skb, XFRMA_ALG_AUTH_TRUNC, xfrm_alg_auth_len(auth));
+ if (!nla)
+ return -EMSGSIZE;
+ ap = nla_data(nla);
+ memcpy(ap, auth, sizeof(struct xfrm_algo_auth));
+ if (redact_secret && auth->alg_key_len)
+ memset(ap->alg_key, 0, (auth->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, auth->alg_key,
+ (auth->alg_key_len + 7) / 8);
+ return 0;
+}
+
+static int copy_to_user_aead(struct xfrm_algo_aead *aead, struct sk_buff *skb)
+{
+ struct nlattr *nla = nla_reserve(skb, XFRMA_ALG_AEAD, aead_len(aead));
+ struct xfrm_algo_aead *ap;
+ bool redact_secret = xfrm_redact();
+
+ if (!nla)
+ return -EMSGSIZE;
+
+ ap = nla_data(nla);
+ memcpy(ap, aead, sizeof(*aead));
+
+ if (redact_secret && aead->alg_key_len)
+ memset(ap->alg_key, 0, (aead->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, aead->alg_key,
+ (aead->alg_key_len + 7) / 8);
+ return 0;
+}
+
+static int copy_to_user_ealg(struct xfrm_algo *ealg, struct sk_buff *skb)
+{
+ struct xfrm_algo *ap;
+ bool redact_secret = xfrm_redact();
+ struct nlattr *nla = nla_reserve(skb, XFRMA_ALG_CRYPT,
+ xfrm_alg_len(ealg));
+ if (!nla)
+ return -EMSGSIZE;
+
+ ap = nla_data(nla);
+ memcpy(ap, ealg, sizeof(*ealg));
+
+ if (redact_secret && ealg->alg_key_len)
+ memset(ap->alg_key, 0, (ealg->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, ealg->alg_key,
+ (ealg->alg_key_len + 7) / 8);
+
return 0;
}
@@ -906,20 +969,17 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
goto out;
}
if (x->aead) {
- ret = nla_put(skb, XFRMA_ALG_AEAD, aead_len(x->aead), x->aead);
+ ret = copy_to_user_aead(x->aead, skb);
if (ret)
goto out;
}
if (x->aalg) {
ret = copy_to_user_auth(x->aalg, skb);
- if (!ret)
- ret = nla_put(skb, XFRMA_ALG_AUTH_TRUNC,
- xfrm_alg_auth_len(x->aalg), x->aalg);
if (ret)
goto out;
}
if (x->ealg) {
- ret = nla_put(skb, XFRMA_ALG_CRYPT, xfrm_alg_len(x->ealg), x->ealg);
+ ret = copy_to_user_ealg(x->ealg, skb);
if (ret)
goto out;
}
diff --git a/security/security.c b/security/security.c
index a28045dc9e7f..abff77c1c8a7 100644
--- a/security/security.c
+++ b/security/security.c
@@ -65,6 +65,7 @@ const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
[LOCKDOWN_PERF] = "unsafe use of perf",
[LOCKDOWN_TRACEFS] = "use of tracefs",
[LOCKDOWN_XMON_RW] = "xmon read and write access",
+ [LOCKDOWN_XFRM_SECRET] = "xfrm SA secret",
[LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
};
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: pull request (net-next): ipsec-next 2020-12-12
2020-12-12 8:57 pull request (net-next): ipsec-next 2020-12-12 Steffen Klassert
2020-12-12 8:57 ` [PATCH] xfrm: redact SA secret with lockdown confidentiality Steffen Klassert
@ 2020-12-12 21:40 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 7+ messages in thread
From: patchwork-bot+netdevbpf @ 2020-12-12 21:40 UTC (permalink / raw)
To: Steffen Klassert; +Cc: davem, kuba, herbert, netdev
Hello:
This pull request was applied to netdev/net-next.git (refs/heads/master):
On Sat, 12 Dec 2020 09:57:36 +0100 you wrote:
> Just one patch this time:
>
> 1) Redact the SA keys with kernel lockdown confidentiality.
> If enabled, no secret keys are sent to uuserspace.
> From Antony Antony.
>
> Please pull or let me know if there are problems.
>
> [...]
Here is the summary with links:
- pull request (net-next): ipsec-next 2020-12-12
https://git.kernel.org/netdev/net-next/c/e2437ac2f59d
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH ipsec-next] xfrm: add /proc/sys/core/net/xfrm_redact_secret
@ 2020-07-28 15:47 Antony Antony
2020-10-16 13:36 ` [PATCH] xfrm: redact SA secret with lockdown confidentiality Antony Antony
0 siblings, 1 reply; 7+ messages in thread
From: Antony Antony @ 2020-07-28 15:47 UTC (permalink / raw)
To: Steffen Klassert, netdev; +Cc: Herbert Xu, Stephan Müller, Antony Antony
when enabled, 1, redact XFRM SA secret in the netlink response to
xfrm_get_sa() or dump all sa.
e.g
echo 1 > /proc/sys/net/core/xfrm_redact_secret
ip xfrm state
src 172.16.1.200 dst 172.16.1.100
proto esp spi 0x00000002 reqid 2 mode tunnel
replay-window 0
aead rfc4106(gcm(aes)) 0x0000000000000000000000000000000000000000 96
the aead secret is redacted.
/proc/sys/core/net/xfrm_redact_secret is a toggle.
Once enabled, either at compile or via proc, it can not be disabled.
Redacting secret is a FIPS 140-2 requirement.
Cc: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Antony Antony <antony.antony@secunet.com>
---
Documentation/networking/xfrm_sysctl.rst | 7 +++
include/net/netns/xfrm.h | 1 +
net/xfrm/Kconfig | 10 ++++
net/xfrm/xfrm_sysctl.c | 20 +++++++
net/xfrm/xfrm_user.c | 76 +++++++++++++++++++++---
5 files changed, 105 insertions(+), 9 deletions(-)
diff --git a/Documentation/networking/xfrm_sysctl.rst b/Documentation/networking/xfrm_sysctl.rst
index 47b9bbdd0179..26432b0ff3ac 100644
--- a/Documentation/networking/xfrm_sysctl.rst
+++ b/Documentation/networking/xfrm_sysctl.rst
@@ -9,3 +9,10 @@ XFRM Syscall
xfrm_acq_expires - INTEGER
default 30 - hard timeout in seconds for acquire requests
+
+xfrm_redact_secret - INTEGER
+ A toggle to redact xfrm SA's secret to userspace.
+ When true the kernel, netlink message will redact SA secret
+ to userspace. This is part of FIPS 140-2 requirement.
+ Once the value is set to true, either at compile or at run time,
+ it can not be set to false.
diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h
index 59f45b1e9dac..0ca9328daad4 100644
--- a/include/net/netns/xfrm.h
+++ b/include/net/netns/xfrm.h
@@ -64,6 +64,7 @@ struct netns_xfrm {
u32 sysctl_aevent_rseqth;
int sysctl_larval_drop;
u32 sysctl_acq_expires;
+ u32 sysctl_redact_secret;
#ifdef CONFIG_SYSCTL
struct ctl_table_header *sysctl_hdr;
#endif
diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index 5b9a5ab48111..270a4e906a15 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -91,6 +91,16 @@ config XFRM_ESP
select CRYPTO_SEQIV
select CRYPTO_SHA256
+config XFRM_REDACT_SECRET
+ bool "Redact xfrm SA secret in netlink message"
+ depends on SYSCTL
+ default n
+ help
+ Enable XFRM SA secret redact in the netlink message.
+ Redacting secret is a FIPS 140-2 requirement.
+ Once enabled at compile, the value can not be set to false on
+ a running system.
+
config XFRM_IPCOMP
tristate
select XFRM_ALGO
diff --git a/net/xfrm/xfrm_sysctl.c b/net/xfrm/xfrm_sysctl.c
index 0c6c5ef65f9d..a41aa325a478 100644
--- a/net/xfrm/xfrm_sysctl.c
+++ b/net/xfrm/xfrm_sysctl.c
@@ -4,15 +4,25 @@
#include <net/net_namespace.h>
#include <net/xfrm.h>
+#ifdef CONFIG_SYSCTL
+#ifdef CONFIG_XFRM_REDACT_SECRET
+#define XFRM_REDACT_SECRET 1
+#else
+#define XFRM_REDACT_SECRET 0
+#endif
+#endif
+
static void __net_init __xfrm_sysctl_init(struct net *net)
{
net->xfrm.sysctl_aevent_etime = XFRM_AE_ETIME;
net->xfrm.sysctl_aevent_rseqth = XFRM_AE_SEQT_SIZE;
net->xfrm.sysctl_larval_drop = 1;
net->xfrm.sysctl_acq_expires = 30;
+ net->xfrm.sysctl_redact_secret = XFRM_REDACT_SECRET;
}
#ifdef CONFIG_SYSCTL
+
static struct ctl_table xfrm_table[] = {
{
.procname = "xfrm_aevent_etime",
@@ -38,6 +48,15 @@ static struct ctl_table xfrm_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec
},
+ {
+ .procname = "xfrm_redact_secret",
+ .maxlen = sizeof(u32),
+ .mode = 0644,
+ /* only handle a transition from "0" to "1" */
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ONE,
+ .extra2 = SYSCTL_ONE,
+ },
{}
};
@@ -54,6 +73,7 @@ int __net_init xfrm_sysctl_init(struct net *net)
table[1].data = &net->xfrm.sysctl_aevent_rseqth;
table[2].data = &net->xfrm.sysctl_larval_drop;
table[3].data = &net->xfrm.sysctl_acq_expires;
+ table[4].data = &net->xfrm.sysctl_redact_secret;
/* Don't export sysctls to unprivileged users */
if (net->user_ns != &init_user_ns)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index e6cfaa680ef3..a3e89dddea9d 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -848,21 +848,78 @@ static int copy_user_offload(struct xfrm_state_offload *xso, struct sk_buff *skb
return 0;
}
-static int copy_to_user_auth(struct xfrm_algo_auth *auth, struct sk_buff *skb)
+static int copy_to_user_auth(u32 redact_secret, struct xfrm_algo_auth *auth,
+ struct sk_buff *skb)
{
struct xfrm_algo *algo;
+ struct xfrm_algo_auth *ap;
struct nlattr *nla;
nla = nla_reserve(skb, XFRMA_ALG_AUTH,
sizeof(*algo) + (auth->alg_key_len + 7) / 8);
if (!nla)
return -EMSGSIZE;
-
algo = nla_data(nla);
strncpy(algo->alg_name, auth->alg_name, sizeof(algo->alg_name));
- memcpy(algo->alg_key, auth->alg_key, (auth->alg_key_len + 7) / 8);
+
+ if (redact_secret && auth->alg_key_len)
+ memset(algo->alg_key, 0, (auth->alg_key_len + 7) / 8);
+ else
+ memcpy(algo->alg_key, auth->alg_key,
+ (auth->alg_key_len + 7) / 8);
algo->alg_key_len = auth->alg_key_len;
+ nla = nla_reserve(skb, XFRMA_ALG_AUTH_TRUNC, xfrm_alg_auth_len(auth));
+ if (!nla)
+ return -EMSGSIZE;
+ ap = nla_data(nla);
+ memcpy(ap, auth, sizeof(struct xfrm_algo_auth));
+ if (redact_secret)
+ memset(ap->alg_key, 0, (auth->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, auth->alg_key,
+ (auth->alg_key_len + 7) / 8);
+ return 0;
+}
+
+static int copy_to_user_aead(u32 redact_secret,
+ struct xfrm_algo_aead *aead, struct sk_buff *skb)
+{
+ struct nlattr *nla = nla_reserve(skb, XFRMA_ALG_AEAD, aead_len(aead));
+ struct xfrm_algo_aead *ap;
+
+ if (!nla)
+ return -EMSGSIZE;
+
+ ap = nla_data(nla);
+ memcpy(ap, aead, sizeof(*aead));
+
+ if (redact_secret)
+ memset(ap->alg_key, 0, (aead->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, aead->alg_key,
+ (aead->alg_key_len + 7) / 8);
+ return 0;
+}
+
+static int copy_to_user_ealg(u32 redact_secret, struct xfrm_algo *ealg,
+ struct sk_buff *skb)
+{
+ struct xfrm_algo *ap;
+ struct nlattr *nla = nla_reserve(skb, XFRMA_ALG_CRYPT,
+ xfrm_alg_len(ealg));
+ if (!nla)
+ return -EMSGSIZE;
+
+ ap = nla_data(nla);
+ memcpy(ap, ealg, sizeof(*ealg));
+
+ if (redact_secret)
+ memset(ap->alg_key, 0, (ealg->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, ealg->alg_key,
+ (ealg->alg_key_len + 7) / 8);
+
return 0;
}
@@ -884,6 +941,7 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
struct sk_buff *skb)
{
int ret = 0;
+ struct net *net = xs_net(x);
copy_to_user_state(x, p);
@@ -906,20 +964,20 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
goto out;
}
if (x->aead) {
- ret = nla_put(skb, XFRMA_ALG_AEAD, aead_len(x->aead), x->aead);
+ ret = copy_to_user_aead(net->xfrm.sysctl_redact_secret,
+ x->aead, skb);
if (ret)
goto out;
}
if (x->aalg) {
- ret = copy_to_user_auth(x->aalg, skb);
- if (!ret)
- ret = nla_put(skb, XFRMA_ALG_AUTH_TRUNC,
- xfrm_alg_auth_len(x->aalg), x->aalg);
+ ret = copy_to_user_auth(net->xfrm.sysctl_redact_secret,
+ x->aalg, skb);
if (ret)
goto out;
}
if (x->ealg) {
- ret = nla_put(skb, XFRMA_ALG_CRYPT, xfrm_alg_len(x->ealg), x->ealg);
+ ret = copy_to_user_ealg(net->xfrm.sysctl_redact_secret,
+ x->ealg, skb);
if (ret)
goto out;
}
--
2.20.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH] xfrm: redact SA secret with lockdown confidentiality
2020-07-28 15:47 [PATCH ipsec-next] xfrm: add /proc/sys/core/net/xfrm_redact_secret Antony Antony
@ 2020-10-16 13:36 ` Antony Antony
2020-10-31 10:49 ` Steffen Klassert
0 siblings, 1 reply; 7+ messages in thread
From: Antony Antony @ 2020-10-16 13:36 UTC (permalink / raw)
To: Steffen Klassert, Herbert Xu, David S. Miller, Jakub Kicinski
Cc: netdev, linux-security-module, Antony Antony, Antony Antony,
Stephan Mueller
redact XFRM SA secret in the netlink response to xfrm_get_sa()
or dumpall sa.
Enable this at build time and set kernel lockdown to confidentiality.
e.g.
cat /sys/kernel/security/lockdown
none integrity [confidentiality]
ip xfrm state
src 172.16.1.200 dst 172.16.1.100
proto esp spi 0x00000002 reqid 2 mode tunnel
replay-window 0
aead rfc4106(gcm(aes)) 0x0000000000000000000000000000000000000000 96
note: the aead secret is redacted.
Redacting secret is also a FIPS 140-2 requirement.
v1->v2
- add size checks before memset calls
v2->v3
- replace spaces with tabs for consistency
v3->v4
- use kernel lockdown instead of a /proc setting
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Antony Antony <antony.antony@secunet.com>
---
include/linux/security.h | 1 +
net/xfrm/Kconfig | 9 +++++
net/xfrm/xfrm_user.c | 76 ++++++++++++++++++++++++++++++++++++----
security/security.c | 1 +
4 files changed, 80 insertions(+), 7 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 0a0a03b36a3b..8438970473b1 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -126,6 +126,7 @@ enum lockdown_reason {
LOCKDOWN_PERF,
LOCKDOWN_TRACEFS,
LOCKDOWN_XMON_RW,
+ LOCKDOWN_XFRM_SECRET,
LOCKDOWN_CONFIDENTIALITY_MAX,
};
diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index 5b9a5ab48111..cb592524701d 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -91,6 +91,15 @@ config XFRM_ESP
select CRYPTO_SEQIV
select CRYPTO_SHA256
+config XFRM_REDACT_SECRET
+ bool "Redact xfrm SA secret"
+ depends on XFRM && SECURITY_LOCKDOWN_LSM
+ default n
+ help
+ Redats XFRM SA secret in the netlink message to user space.
+ Redacting secret is also a FIPS 140-2 requirement.
+ e.g. ip xfrm state; will show redacted the SA secret.
+
config XFRM_IPCOMP
tristate
select XFRM_ALGO
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index fbb7d9d06478..b57599d050dc 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -11,6 +11,7 @@
*
*/
+#include <linux/fips.h>
#include <linux/crypto.h>
#include <linux/module.h>
#include <linux/kernel.h>
@@ -848,21 +849,85 @@ static int copy_user_offload(struct xfrm_state_offload *xso, struct sk_buff *skb
return 0;
}
+static bool xfrm_redact(void)
+{
+ return IS_ENABLED(CONFIG_SECURITY) &&
+ IS_ENABLED(CONFIG_XFRM_REDACT_SECRET) &&
+ security_locked_down(LOCKDOWN_XFRM_SECRET);
+}
+
static int copy_to_user_auth(struct xfrm_algo_auth *auth, struct sk_buff *skb)
{
struct xfrm_algo *algo;
+ struct xfrm_algo_auth *ap;
struct nlattr *nla;
+ bool redact_secret = xfrm_redact();
nla = nla_reserve(skb, XFRMA_ALG_AUTH,
sizeof(*algo) + (auth->alg_key_len + 7) / 8);
if (!nla)
return -EMSGSIZE;
-
algo = nla_data(nla);
strncpy(algo->alg_name, auth->alg_name, sizeof(algo->alg_name));
- memcpy(algo->alg_key, auth->alg_key, (auth->alg_key_len + 7) / 8);
+
+ if (redact_secret && auth->alg_key_len)
+ memset(algo->alg_key, 0, (auth->alg_key_len + 7) / 8);
+ else
+ memcpy(algo->alg_key, auth->alg_key,
+ (auth->alg_key_len + 7) / 8);
algo->alg_key_len = auth->alg_key_len;
+ nla = nla_reserve(skb, XFRMA_ALG_AUTH_TRUNC, xfrm_alg_auth_len(auth));
+ if (!nla)
+ return -EMSGSIZE;
+ ap = nla_data(nla);
+ memcpy(ap, auth, sizeof(struct xfrm_algo_auth));
+ if (redact_secret && auth->alg_key_len)
+ memset(ap->alg_key, 0, (auth->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, auth->alg_key,
+ (auth->alg_key_len + 7) / 8);
+ return 0;
+}
+
+static int copy_to_user_aead(struct xfrm_algo_aead *aead, struct sk_buff *skb)
+{
+ struct nlattr *nla = nla_reserve(skb, XFRMA_ALG_AEAD, aead_len(aead));
+ struct xfrm_algo_aead *ap;
+ bool redact_secret = xfrm_redact();
+
+ if (!nla)
+ return -EMSGSIZE;
+
+ ap = nla_data(nla);
+ memcpy(ap, aead, sizeof(*aead));
+
+ if (redact_secret && aead->alg_key_len)
+ memset(ap->alg_key, 0, (aead->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, aead->alg_key,
+ (aead->alg_key_len + 7) / 8);
+ return 0;
+}
+
+static int copy_to_user_ealg(struct xfrm_algo *ealg, struct sk_buff *skb)
+{
+ struct xfrm_algo *ap;
+ bool redact_secret = xfrm_redact();
+ struct nlattr *nla = nla_reserve(skb, XFRMA_ALG_CRYPT,
+ xfrm_alg_len(ealg));
+ if (!nla)
+ return -EMSGSIZE;
+
+ ap = nla_data(nla);
+ memcpy(ap, ealg, sizeof(*ealg));
+
+ if (redact_secret && ealg->alg_key_len)
+ memset(ap->alg_key, 0, (ealg->alg_key_len + 7) / 8);
+ else
+ memcpy(ap->alg_key, ealg->alg_key,
+ (ealg->alg_key_len + 7) / 8);
+
return 0;
}
@@ -906,20 +971,17 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
goto out;
}
if (x->aead) {
- ret = nla_put(skb, XFRMA_ALG_AEAD, aead_len(x->aead), x->aead);
+ ret = copy_to_user_aead(x->aead, skb);
if (ret)
goto out;
}
if (x->aalg) {
ret = copy_to_user_auth(x->aalg, skb);
- if (!ret)
- ret = nla_put(skb, XFRMA_ALG_AUTH_TRUNC,
- xfrm_alg_auth_len(x->aalg), x->aalg);
if (ret)
goto out;
}
if (x->ealg) {
- ret = nla_put(skb, XFRMA_ALG_CRYPT, xfrm_alg_len(x->ealg), x->ealg);
+ ret = copy_to_user_ealg(x->ealg, skb);
if (ret)
goto out;
}
diff --git a/security/security.c b/security/security.c
index 70a7ad357bc6..72d9aac7178a 100644
--- a/security/security.c
+++ b/security/security.c
@@ -64,6 +64,7 @@ const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
[LOCKDOWN_PERF] = "unsafe use of perf",
[LOCKDOWN_TRACEFS] = "use of tracefs",
[LOCKDOWN_XMON_RW] = "xmon read and write access",
+ [LOCKDOWN_XFRM_SECRET] = "xfrm SA secret",
[LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
};
--
2.20.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] xfrm: redact SA secret with lockdown confidentiality
2020-10-16 13:36 ` [PATCH] xfrm: redact SA secret with lockdown confidentiality Antony Antony
@ 2020-10-31 10:49 ` Steffen Klassert
2020-11-17 16:46 ` Antony Antony
0 siblings, 1 reply; 7+ messages in thread
From: Steffen Klassert @ 2020-10-31 10:49 UTC (permalink / raw)
To: Antony Antony
Cc: Herbert Xu, David S. Miller, Jakub Kicinski, netdev,
linux-security-module, Antony Antony, Stephan Mueller
On Fri, Oct 16, 2020 at 03:36:12PM +0200, Antony Antony wrote:
> redact XFRM SA secret in the netlink response to xfrm_get_sa()
> or dumpall sa.
> Enable this at build time and set kernel lockdown to confidentiality.
Wouldn't it be better to enable is at boot or runtime? This defaults
to 'No' at build time, so distibutions will not compile it in. That
means that noone who uses a kernel that comes with a Linux distribution
can use that.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] xfrm: redact SA secret with lockdown confidentiality
2020-10-31 10:49 ` Steffen Klassert
@ 2020-11-17 16:46 ` Antony Antony
0 siblings, 0 replies; 7+ messages in thread
From: Antony Antony @ 2020-11-17 16:46 UTC (permalink / raw)
To: Steffen Klassert
Cc: Antony Antony, Herbert Xu, David S. Miller, Jakub Kicinski,
netdev, linux-security-module, Antony Antony, Stephan Mueller
On Sat, Oct 31, 2020 at 11:49:11 +0100, Steffen Klassert wrote:
> On Fri, Oct 16, 2020 at 03:36:12PM +0200, Antony Antony wrote:
> > redact XFRM SA secret in the netlink response to xfrm_get_sa()
> > or dumpall sa.
> > Enable this at build time and set kernel lockdown to confidentiality.
>
> Wouldn't it be better to enable is at boot or runtime? This defaults
> to 'No' at build time, so distibutions will not compile it in. That
> means that noone who uses a kernel that comes with a Linux distribution
> can use that.
It is a good idea. I will send new version soon.
thanks,
-antony
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-12-12 21:41 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-12 8:57 pull request (net-next): ipsec-next 2020-12-12 Steffen Klassert
2020-12-12 8:57 ` [PATCH] xfrm: redact SA secret with lockdown confidentiality Steffen Klassert
2020-12-12 21:40 ` patchwork-bot+netdevbpf
2020-12-12 21:40 ` pull request (net-next): ipsec-next 2020-12-12 patchwork-bot+netdevbpf
-- strict thread matches above, loose matches on Subject: below --
2020-07-28 15:47 [PATCH ipsec-next] xfrm: add /proc/sys/core/net/xfrm_redact_secret Antony Antony
2020-10-16 13:36 ` [PATCH] xfrm: redact SA secret with lockdown confidentiality Antony Antony
2020-10-31 10:49 ` Steffen Klassert
2020-11-17 16:46 ` Antony Antony
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