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From: David Howells <dhowells@redhat.com>
To: keyrings@vger.kernel.org
Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 2/7] keys: sparse: Fix incorrect RCU accesses
Date: Wed, 22 May 2019 23:28:17 +0100	[thread overview]
Message-ID: <155856409697.10428.15024260088836364169.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <155856408314.10428.17035328117829912815.stgit@warthog.procyon.org.uk>

Fix a pair of accesses that should be using RCU protection.

rcu_dereference_protected() is needed to access task_struct::real_parent.

current_cred() should be used to access current->cred.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 security/keys/keyctl.c           |    3 ++-
 security/keys/request_key_auth.c |    2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 3e4053a217c3..0f947bcbad46 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1524,7 +1524,8 @@ long keyctl_session_to_parent(void)
 
 	ret = -EPERM;
 	oldwork = NULL;
-	parent = me->real_parent;
+	parent = rcu_dereference_protected(me->real_parent,
+					   lockdep_is_held(&tasklist_lock));
 
 	/* the parent mustn't be init and mustn't be a kernel thread */
 	if (parent->pid <= 1 || !parent->mm)
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index bda6201c6c45..572c7a60473a 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -152,7 +152,7 @@ struct key *request_key_auth_new(struct key *target, const char *op,
 				 struct key *dest_keyring)
 {
 	struct request_key_auth *rka, *irka;
-	const struct cred *cred = current->cred;
+	const struct cred *cred = current_cred();
 	struct key *authkey = NULL;
 	char desc[20];
 	int ret = -ENOMEM;


  parent reply	other threads:[~2019-05-22 22:28 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22 22:28 [PATCH 0/7] keys: Miscellany David Howells
2019-05-22 22:28 ` [PATCH 1/7] keys: sparse: Fix key_fs[ug]id_changed() David Howells
2019-05-24 19:38   ` James Morris
2019-05-22 22:28 ` David Howells [this message]
2019-05-25  3:57   ` [PATCH 2/7] keys: sparse: Fix incorrect RCU accesses James Morris
2019-05-22 22:28 ` [PATCH 3/7] keys: sparse: Fix kdoc mismatches David Howells
2019-05-25  3:57   ` James Morris
2019-05-22 22:28 ` [PATCH 4/7] keys: Break bits out of key_unlink() David Howells
2019-05-28 20:41   ` James Morris
2019-05-22 22:28 ` [PATCH 5/7] keys: Make __key_link_begin() handle lockdep nesting David Howells
2019-05-28 20:42   ` James Morris
2019-05-22 22:28 ` [PATCH 6/7] keys: Add a keyctl to move a key between keyrings David Howells
2019-05-28 20:51   ` James Morris
2019-05-29 21:34   ` David Howells
2019-05-29 23:25   ` Eric Biggers
2019-05-30 13:31   ` David Howells
2019-05-22 22:28 ` [PATCH 7/7] keys: Grant Link permission to possessers of request_key auth keys David Howells
2019-05-28 21:01   ` James Morris

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