diff options
| -rw-r--r-- | fs/open.c | 4 | ||||
| -rw-r--r-- | include/linux/security.h | 18 | ||||
| -rw-r--r-- | security/dummy.c | 6 | ||||
| -rw-r--r-- | security/selinux/avc.c | 5 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 53 | ||||
| -rw-r--r-- | security/selinux/include/avc.h | 2 | ||||
| -rw-r--r-- | security/selinux/include/objsec.h | 2 |
7 files changed, 89 insertions, 1 deletions
diff --git a/fs/open.c b/fs/open.c index 1d9e5e98bf4e..044bfa891c94 100644 --- a/fs/open.c +++ b/fs/open.c @@ -757,6 +757,10 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, f->f_op = fops_get(inode->i_fop); file_move(f, &inode->i_sb->s_files); + error = security_dentry_open(f); + if (error) + goto cleanup_all; + if (!open && f->f_op) open = f->f_op->open; if (open) { diff --git a/include/linux/security.h b/include/linux/security.h index 1a15526e9f67..928d4793c6f4 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -504,6 +504,13 @@ struct request_sock; * @file contains the file structure being received. * Return 0 if permission is granted. * + * Security hook for dentry + * + * @dentry_open + * Save open-time permission checking state for later use upon + * file_permission, and recheck access if anything has changed + * since inode_permission. + * * Security hooks for task operations. * * @task_create: @@ -1256,6 +1263,7 @@ struct security_operations { int (*file_send_sigiotask) (struct task_struct * tsk, struct fown_struct * fown, int sig); int (*file_receive) (struct file * file); + int (*dentry_open) (struct file *file); int (*task_create) (unsigned long clone_flags); int (*task_alloc_security) (struct task_struct * p); @@ -1864,6 +1872,11 @@ static inline int security_file_receive (struct file *file) return security_ops->file_receive (file); } +static inline int security_dentry_open (struct file *file) +{ + return security_ops->dentry_open (file); +} + static inline int security_task_create (unsigned long clone_flags) { return security_ops->task_create (clone_flags); @@ -2546,6 +2559,11 @@ static inline int security_file_receive (struct file *file) return 0; } +static inline int security_dentry_open (struct file *file) +{ + return 0; +} + static inline int security_task_create (unsigned long clone_flags) { return 0; diff --git a/security/dummy.c b/security/dummy.c index 853ec2292798..64b647a0d9a6 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -463,6 +463,11 @@ static int dummy_file_receive (struct file *file) return 0; } +static int dummy_dentry_open (struct file *file) +{ + return 0; +} + static int dummy_task_create (unsigned long clone_flags) { return 0; @@ -1033,6 +1038,7 @@ void security_fixup_ops (struct security_operations *ops) set_to_dummy_if_null(ops, file_set_fowner); set_to_dummy_if_null(ops, file_send_sigiotask); set_to_dummy_if_null(ops, file_receive); + set_to_dummy_if_null(ops, dentry_open); set_to_dummy_if_null(ops, task_create); set_to_dummy_if_null(ops, task_alloc_security); set_to_dummy_if_null(ops, task_free_security); diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 0e69adf63bdb..81b3dff3cbf0 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -916,3 +916,8 @@ int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata); return rc; } + +u32 avc_policy_seqno(void) +{ + return avc_cache.latest_notif; +} diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index cf76150e623e..97b7e2738097 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -14,6 +14,8 @@ * <dgoeddel@trustedcs.com> * Copyright (C) 2006 Hewlett-Packard Development Company, L.P. * Paul Moore, <paul.moore@hp.com> + * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. + * Yuichi Nakamura <ynakam@hitachisoft.jp> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, @@ -2464,7 +2466,7 @@ static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t /* file security operations */ -static int selinux_file_permission(struct file *file, int mask) +static int selinux_revalidate_file_permission(struct file *file, int mask) { int rc; struct inode *inode = file->f_path.dentry->d_inode; @@ -2486,6 +2488,25 @@ static int selinux_file_permission(struct file *file, int mask) return selinux_netlbl_inode_permission(inode, mask); } +static int selinux_file_permission(struct file *file, int mask) +{ + struct inode *inode = file->f_path.dentry->d_inode; + struct task_security_struct *tsec = current->security; + struct file_security_struct *fsec = file->f_security; + struct inode_security_struct *isec = inode->i_security; + + if (!mask) { + /* No permission to check. Existence test. */ + return 0; + } + + if (tsec->sid == fsec->sid && fsec->isid == isec->sid + && fsec->pseqno == avc_policy_seqno()) + return selinux_netlbl_inode_permission(inode, mask); + + return selinux_revalidate_file_permission(file, mask); +} + static int selinux_file_alloc_security(struct file *file) { return file_alloc_security(file); @@ -2725,6 +2746,34 @@ static int selinux_file_receive(struct file *file) return file_has_perm(current, file, file_to_av(file)); } +static int selinux_dentry_open(struct file *file) +{ + struct file_security_struct *fsec; + struct inode *inode; + struct inode_security_struct *isec; + inode = file->f_path.dentry->d_inode; + fsec = file->f_security; + isec = inode->i_security; + /* + * Save inode label and policy sequence number + * at open-time so that selinux_file_permission + * can determine whether revalidation is necessary. + * Task label is already saved in the file security + * struct as its SID. + */ + fsec->isid = isec->sid; + fsec->pseqno = avc_policy_seqno(); + /* + * Since the inode label or policy seqno may have changed + * between the selinux_inode_permission check and the saving + * of state above, recheck that access is still permitted. + * Otherwise, access might never be revalidated against the + * new inode label or new policy. + * This check is not redundant - do not remove. + */ + return inode_has_perm(current, inode, file_to_av(file), NULL); +} + /* task security operations */ static int selinux_task_create(unsigned long clone_flags) @@ -4794,6 +4843,8 @@ static struct security_operations selinux_ops = { .file_send_sigiotask = selinux_file_send_sigiotask, .file_receive = selinux_file_receive, + .dentry_open = selinux_dentry_open, + .task_create = selinux_task_create, .task_alloc_security = selinux_task_alloc_security, .task_free_security = selinux_task_free_security, diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h index e145f6e13b0b..553607a19e92 100644 --- a/security/selinux/include/avc.h +++ b/security/selinux/include/avc.h @@ -112,6 +112,8 @@ int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, u32 requested, struct avc_audit_data *auditdata); +u32 avc_policy_seqno(void); + #define AVC_CALLBACK_GRANT 1 #define AVC_CALLBACK_TRY_REVOKE 2 #define AVC_CALLBACK_REVOKE 4 diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 91b88f0ba20c..642a9fd319ad 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -53,6 +53,8 @@ struct file_security_struct { struct file *file; /* back pointer to file object */ u32 sid; /* SID of open file description */ u32 fown_sid; /* SID of file owner (for SIGIO) */ + u32 isid; /* SID of inode at the time of file open */ + u32 pseqno; /* Policy seqno at the time of file open */ }; struct superblock_security_struct { |