diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/selinux/hooks.c | 28 | ||||
| -rw-r--r-- | security/selinux/include/objsec.h | 5 |
2 files changed, 27 insertions, 6 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 419491d..57b0b49 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -234,6 +234,14 @@ static int inode_alloc_security(struct inode *inode) return 0; } +static void inode_free_rcu(struct rcu_head *head) +{ + struct inode_security_struct *isec; + + isec = container_of(head, struct inode_security_struct, rcu); + kmem_cache_free(sel_inode_cache, isec); +} + static void inode_free_security(struct inode *inode) { struct inode_security_struct *isec = inode->i_security; @@ -244,8 +252,16 @@ static void inode_free_security(struct inode *inode) list_del_init(&isec->list); spin_unlock(&sbsec->isec_lock); - inode->i_security = NULL; - kmem_cache_free(sel_inode_cache, isec); + /* + * The inode may still be referenced in a path walk and + * a call to selinux_inode_permission() can be made + * after inode_free_security() is called. Ideally, the VFS + * wouldn't do this, but fixing that is a much harder + * job. For now, simply free the i_security via RCU, and + * leave the current inode->i_security pointer intact. + * The inode will be freed after the RCU grace period too. + */ + call_rcu(&isec->rcu, inode_free_rcu); } static int file_alloc_security(struct file *file) @@ -4334,8 +4350,10 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) } err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, PEER__RECV, &ad); - if (err) + if (err) { selinux_netlbl_err(skb, err, 0); + return err; + } } if (secmark_active) { @@ -5586,11 +5604,11 @@ static int selinux_setprocattr(struct task_struct *p, /* Check for ptracing, and update the task SID if ok. Otherwise, leave SID unchanged and fail. */ ptsid = 0; - task_lock(p); + rcu_read_lock(); tracer = ptrace_parent(p); if (tracer) ptsid = task_sid(tracer); - task_unlock(p); + rcu_read_unlock(); if (tracer) { error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index b1dfe10..078e553 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -38,7 +38,10 @@ struct task_security_struct { struct inode_security_struct { struct inode *inode; /* back pointer to inode object */ - struct list_head list; /* list of inode_security_struct */ + union { + struct list_head list; /* list of inode_security_struct */ + struct rcu_head rcu; /* for freeing the inode_security_struct */ + }; u32 task_sid; /* SID of creating task */ u32 sid; /* SID of this object */ u16 sclass; /* security class of this object */ |
