diff options
Diffstat (limited to 'security/selinux/hooks.c')
| -rw-r--r-- | security/selinux/hooks.c | 133 |
1 files changed, 127 insertions, 6 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 20219ef..b62384d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -215,6 +215,14 @@ 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; @@ -225,8 +233,16 @@ 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) @@ -403,8 +419,11 @@ static int sb_finish_set_opts(struct super_block *sb) sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) sbsec->flags &= ~SE_SBLABELSUPP; - /* Special handling for sysfs. Is genfs but also has setxattr handler*/ - if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0) + /* Special handling. Is genfs but also has in-core setxattr handler*/ + if (!strcmp(sb->s_type->name, "sysfs") || + !strcmp(sb->s_type->name, "pstore") || + !strcmp(sb->s_type->name, "debugfs") || + !strcmp(sb->s_type->name, "rootfs")) sbsec->flags |= SE_SBLABELSUPP; /* Initialize the root inode. */ @@ -421,6 +440,7 @@ next_inode: list_entry(sbsec->isec_head.next, struct inode_security_struct, list); struct inode *inode = isec->inode; + list_del_init(&isec->list); spin_unlock(&sbsec->isec_lock); inode = igrab(inode); if (inode) { @@ -429,7 +449,6 @@ next_inode: iput(inode); } spin_lock(&sbsec->isec_lock); - list_del_init(&isec->list); goto next_inode; } spin_unlock(&sbsec->isec_lock); @@ -1805,6 +1824,65 @@ static inline u32 open_file_to_av(struct file *file) /* Hook functions begin here. */ +static int selinux_binder_set_context_mgr(struct task_struct *mgr) +{ + u32 mysid = current_sid(); + u32 mgrsid = task_sid(mgr); + + return avc_has_perm(mysid, mgrsid, SECCLASS_BINDER, BINDER__SET_CONTEXT_MGR, NULL); +} + +static int selinux_binder_transaction(struct task_struct *from, struct task_struct *to) +{ + u32 mysid = current_sid(); + u32 fromsid = task_sid(from); + u32 tosid = task_sid(to); + int rc; + + if (mysid != fromsid) { + rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER, BINDER__IMPERSONATE, NULL); + if (rc) + return rc; + } + + return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__CALL, NULL); +} + +static int selinux_binder_transfer_binder(struct task_struct *from, struct task_struct *to) +{ + u32 fromsid = task_sid(from); + u32 tosid = task_sid(to); + return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, NULL); +} + +static int selinux_binder_transfer_file(struct task_struct *from, struct task_struct *to, struct file *file) +{ + u32 sid = task_sid(to); + struct file_security_struct *fsec = file->f_security; + struct inode *inode = file->f_path.dentry->d_inode; + struct inode_security_struct *isec = inode->i_security; + struct common_audit_data ad; + int rc; + + COMMON_AUDIT_DATA_INIT(&ad, PATH); + ad.u.path = file->f_path; + + if (sid != fsec->sid) { + rc = avc_has_perm(sid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + return rc; + } + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file), + &ad); +} + static int selinux_ptrace_access_check(struct task_struct *child, unsigned int mode) { @@ -2964,6 +3042,44 @@ static void selinux_file_free_security(struct file *file) file_free_security(file); } +/* + * Check whether a task has the ioctl permission and cmd + * operation to an inode. + */ +int ioctl_has_perm(const struct cred *cred, struct file *file, + u32 requested, u16 cmd) +{ + struct common_audit_data ad; + struct file_security_struct *fsec = file->f_security; + struct inode *inode = file->f_path.dentry->d_inode; + struct inode_security_struct *isec = inode->i_security; + struct lsm_ioctlop_audit ioctl; + u32 ssid = cred_sid(cred); + int rc; + + COMMON_AUDIT_DATA_INIT(&ad, IOCTL_OP); + ad.u.op = &ioctl; + ad.u.op->cmd = cmd; + ad.u.op->path = file->f_path; + + if (ssid != fsec->sid) { + rc = avc_has_perm(ssid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + goto out; + } + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + rc = avc_has_operation(ssid, isec->sid, isec->sclass, + requested, cmd, &ad); +out: + return rc; +} + static int selinux_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3006,7 +3122,7 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd, * to the file's ioctl() function. */ default: - error = file_has_perm(cred, file, FILE__IOCTL); + error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); } return error; } @@ -5457,6 +5573,11 @@ static int selinux_key_getsecurity(struct key *key, char **_buffer) static struct security_operations selinux_ops = { .name = "selinux", + .binder_set_context_mgr = selinux_binder_set_context_mgr, + .binder_transaction = selinux_binder_transaction, + .binder_transfer_binder = selinux_binder_transfer_binder, + .binder_transfer_file = selinux_binder_transfer_file, + .ptrace_access_check = selinux_ptrace_access_check, .ptrace_traceme = selinux_ptrace_traceme, .capget = selinux_capget, |