diff options
Diffstat (limited to 'security/selinux/hooks.c')
-rw-r--r-- | security/selinux/hooks.c | 244 |
1 files changed, 148 insertions, 96 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 1c864c0efe2b..91200feb3f9c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -9,7 +9,8 @@ * James Morris <jmorris@redhat.com> * * Copyright (C) 2001,2002 Networks Associates Technology, Inc. - * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com> + * Eric Paris <eparis@redhat.com> * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. * <dgoeddel@trustedcs.com> * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. @@ -42,9 +43,7 @@ #include <linux/fdtable.h> #include <linux/namei.h> #include <linux/mount.h> -#include <linux/ext2_fs.h> #include <linux/proc_fs.h> -#include <linux/kd.h> #include <linux/netfilter_ipv4.h> #include <linux/netfilter_ipv6.h> #include <linux/tty.h> @@ -53,7 +52,7 @@ #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ #include <net/net_namespace.h> #include <net/netlabel.h> -#include <asm/uaccess.h> +#include <linux/uaccess.h> #include <asm/ioctls.h> #include <asm/atomic.h> #include <linux/bitops.h> @@ -104,7 +103,9 @@ int selinux_enforcing; static int __init enforcing_setup(char *str) { - selinux_enforcing = simple_strtol(str, NULL, 0); + unsigned long enforcing; + if (!strict_strtoul(str, 0, &enforcing)) + selinux_enforcing = enforcing ? 1 : 0; return 1; } __setup("enforcing=", enforcing_setup); @@ -115,7 +116,9 @@ int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; static int __init selinux_enabled_setup(char *str) { - selinux_enabled = simple_strtol(str, NULL, 0); + unsigned long enabled; + if (!strict_strtoul(str, 0, &enabled)) + selinux_enabled = enabled ? 1 : 0; return 1; } __setup("selinux=", selinux_enabled_setup); @@ -123,13 +126,11 @@ __setup("selinux=", selinux_enabled_setup); int selinux_enabled = 1; #endif -/* Original (dummy) security module. */ -static struct security_operations *original_ops; -/* Minimal support for a secondary security module, - just to allow the use of the dummy or capability modules. - The owlsm module can alternatively be used as a secondary - module as long as CONFIG_OWLSM_FD is not enabled. */ +/* + * Minimal support for a secondary security module, + * just to allow the use of the capability module. + */ static struct security_operations *secondary_ops; /* Lists of inode and superblock security structures initialized @@ -554,13 +555,15 @@ static int selinux_set_mnt_opts(struct super_block *sb, struct task_security_struct *tsec = current->security; struct superblock_security_struct *sbsec = sb->s_security; const char *name = sb->s_type->name; - struct inode *inode = sbsec->sb->s_root->d_inode; - struct inode_security_struct *root_isec = inode->i_security; + struct dentry *root = sb->s_root; + struct inode *root_inode = root->d_inode; + struct inode_security_struct *root_isec = root_inode->i_security; u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; u32 defcontext_sid = 0; char **mount_options = opts->mnt_opts; int *flags = opts->mnt_opts_flags; int num_opts = opts->num_mnt_opts; + bool can_xattr = false; mutex_lock(&sbsec->lock); @@ -594,7 +597,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, */ if (sbsec->initialized && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) && (num_opts == 0)) - goto out; + goto out; /* * parse the mount options, check if they are valid sids. @@ -664,14 +667,24 @@ static int selinux_set_mnt_opts(struct super_block *sb, goto out; } - if (strcmp(sb->s_type->name, "proc") == 0) + if (strcmp(name, "proc") == 0) sbsec->proc = 1; + /* + * test if the fs supports xattrs, fs_use might make use of this if the + * fs has no definition in policy. + */ + if (root_inode->i_op->getxattr) { + rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); + if (rc >= 0 || rc == -ENODATA) + can_xattr = true; + } + /* Determine the labeling behavior to use for this filesystem type. */ - rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid); + rc = security_fs_use(name, &sbsec->behavior, &sbsec->sid, can_xattr); if (rc) { printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n", - __func__, sb->s_type->name, rc); + __func__, name, rc); goto out; } @@ -956,6 +969,57 @@ out_err: return rc; } +void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts) +{ + int i; + char *prefix; + + for (i = 0; i < opts->num_mnt_opts; i++) { + char *has_comma = strchr(opts->mnt_opts[i], ','); + + switch (opts->mnt_opts_flags[i]) { + case CONTEXT_MNT: + prefix = CONTEXT_STR; + break; + case FSCONTEXT_MNT: + prefix = FSCONTEXT_STR; + break; + case ROOTCONTEXT_MNT: + prefix = ROOTCONTEXT_STR; + break; + case DEFCONTEXT_MNT: + prefix = DEFCONTEXT_STR; + break; + default: + BUG(); + }; + /* we need a comma before each option */ + seq_putc(m, ','); + seq_puts(m, prefix); + if (has_comma) + seq_putc(m, '\"'); + seq_puts(m, opts->mnt_opts[i]); + if (has_comma) + seq_putc(m, '\"'); + } +} + +static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) +{ + struct security_mnt_opts opts; + int rc; + + rc = selinux_get_mnt_opts(sb, &opts); + if (rc) + return rc; + + selinux_write_opts(m, &opts); + + security_free_mnt_opts(&opts); + + return rc; +} + static inline u16 inode_mode_to_security_class(umode_t mode) { switch (mode & S_IFMT) { @@ -1682,14 +1746,23 @@ static inline u32 file_to_av(struct file *file) /* Hook functions begin here. */ -static int selinux_ptrace(struct task_struct *parent, struct task_struct *child) +static int selinux_ptrace(struct task_struct *parent, + struct task_struct *child, + unsigned int mode) { int rc; - rc = secondary_ops->ptrace(parent, child); + rc = secondary_ops->ptrace(parent, child, mode); if (rc) return rc; + if (mode == PTRACE_MODE_READ) { + struct task_security_struct *tsec = parent->security; + struct task_security_struct *csec = child->security; + return avc_has_perm(tsec->sid, csec->sid, + SECCLASS_FILE, FILE__READ, NULL); + } + return task_has_perm(parent, child, PROCESS__PTRACE); } @@ -2495,7 +2568,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, } if (value && len) { - rc = security_sid_to_context(newsid, &context, &clen); + rc = security_sid_to_context_force(newsid, &context, &clen); if (rc) { kfree(namep); return rc; @@ -2669,6 +2742,11 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name, return rc; rc = security_context_to_sid(value, size, &newsid); + if (rc == -EINVAL) { + if (!capable(CAP_MAC_ADMIN)) + return rc; + rc = security_context_to_sid_force(value, size, &newsid); + } if (rc) return rc; @@ -2690,7 +2768,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name, } static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, - const void *value, size_t size, + const void *value, size_t size, int flags) { struct inode *inode = dentry->d_inode; @@ -2703,10 +2781,11 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, return; } - rc = security_context_to_sid(value, size, &newsid); + rc = security_context_to_sid_force(value, size, &newsid); if (rc) { - printk(KERN_WARNING "%s: unable to obtain SID for context " - "%s, rc=%d\n", __func__, (char *)value, -rc); + printk(KERN_ERR "SELinux: unable to map context to SID" + "for (%s, %lu), rc=%d\n", + inode->i_sb->s_id, inode->i_ino, -rc); return; } @@ -2735,9 +2814,7 @@ static int selinux_inode_removexattr(struct dentry *dentry, const char *name) } /* - * Copy the in-core inode security context value to the user. If the - * getxattr() prior to this succeeded, check to see if we need to - * canonicalize the value to be finally returned to the user. + * Copy the inode security context value to the user. * * Permission check is handled by selinux_inode_getxattr hook. */ @@ -2746,12 +2823,33 @@ static int selinux_inode_getsecurity(const struct inode *inode, const char *name u32 size; int error; char *context = NULL; + struct task_security_struct *tsec = current->security; struct inode_security_struct *isec = inode->i_security; if (strcmp(name, XATTR_SELINUX_SUFFIX)) return -EOPNOTSUPP; - error = security_sid_to_context(isec->sid, &context, &size); + /* + * If the caller has CAP_MAC_ADMIN, then get the raw context + * value even if it is not defined by current policy; otherwise, + * use the in-core value under current policy. + * Use the non-auditing forms of the permission checks since + * getxattr may be called by unprivileged processes commonly + * and lack of permission just means that we fall back to the + * in-core context value, not a denial. + */ + error = secondary_ops->capable(current, CAP_MAC_ADMIN); + if (!error) + error = avc_has_perm_noaudit(tsec->sid, tsec->sid, + SECCLASS_CAPABILITY2, + CAPABILITY2__MAC_ADMIN, + 0, + NULL); + if (!error) + error = security_sid_to_context_force(isec->sid, &context, + &size); + else + error = security_sid_to_context(isec->sid, &context, &size); if (error) return error; error = size; @@ -2865,46 +2963,16 @@ static void selinux_file_free_security(struct file *file) static int selinux_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - int error = 0; - - switch (cmd) { - case FIONREAD: - /* fall through */ - case FIBMAP: - /* fall through */ - case FIGETBSZ: - /* fall through */ - case EXT2_IOC_GETFLAGS: - /* fall through */ - case EXT2_IOC_GETVERSION: - error = file_has_perm(current, file, FILE__GETATTR); - break; - - case EXT2_IOC_SETFLAGS: - /* fall through */ - case EXT2_IOC_SETVERSION: - error = file_has_perm(current, file, FILE__SETATTR); - break; - - /* sys_ioctl() checks */ - case FIONBIO: - /* fall through */ - case FIOASYNC: - error = file_has_perm(current, file, 0); - break; + u32 av = 0; - case KDSKBENT: - case KDSKBSENT: - error = task_has_capability(current, CAP_SYS_TTY_CONFIG); - break; + if (_IOC_DIR(cmd) & _IOC_WRITE) + av |= FILE__WRITE; + if (_IOC_DIR(cmd) & _IOC_READ) + av |= FILE__READ; + if (!av) + av = FILE__IOCTL; - /* default case assumes that the command will go - * to the file's ioctl() function. - */ - default: - error = file_has_perm(current, file, FILE__IOCTL); - } - return error; + return file_has_perm(current, file, av); } static int file_map_prot_check(struct file *file, unsigned long prot, int shared) @@ -3663,7 +3731,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in struct sockaddr_in6 *addr6 = NULL; unsigned short snum; struct sock *sk = sock->sk; - u32 sid, node_perm, addrlen; + u32 sid, node_perm; tsec = current->security; isec = SOCK_INODE(sock)->i_security; @@ -3671,12 +3739,10 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in if (family == PF_INET) { addr4 = (struct sockaddr_in *)address; snum = ntohs(addr4->sin_port); - addrlen = sizeof(addr4->sin_addr.s_addr); addrp = (char *)&addr4->sin_addr.s_addr; } else { addr6 = (struct sockaddr_in6 *)address; snum = ntohs(addr6->sin6_port); - addrlen = sizeof(addr6->sin6_addr.s6_addr); addrp = (char *)&addr6->sin6_addr.s6_addr; } @@ -5047,24 +5113,6 @@ static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) *secid = isec->sid; } -/* module stacking operations */ -static int selinux_register_security(const char *name, struct security_operations *ops) -{ - if (secondary_ops != original_ops) { - printk(KERN_ERR "%s: There is already a secondary security " - "module registered.\n", __func__); - return -EINVAL; - } - - secondary_ops = ops; - - printk(KERN_INFO "%s: Registering secondary module %s\n", - __func__, - name); - - return 0; -} - static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) { if (inode) @@ -5153,6 +5201,12 @@ static int selinux_setprocattr(struct task_struct *p, size--; } error = security_context_to_sid(value, size, &sid); + if (error == -EINVAL && !strcmp(name, "fscreate")) { + if (!capable(CAP_MAC_ADMIN)) + return error; + error = security_context_to_sid_force(value, size, + &sid); + } if (error) return error; } @@ -5186,12 +5240,12 @@ static int selinux_setprocattr(struct task_struct *p, struct task_struct *g, *t; struct mm_struct *mm = p->mm; read_lock(&tasklist_lock); - do_each_thread(g, t) + do_each_thread(g, t) { if (t->mm == mm && t != p) { read_unlock(&tasklist_lock); return -EPERM; } - while_each_thread(g, t); + } while_each_thread(g, t); read_unlock(&tasklist_lock); } @@ -5343,10 +5397,10 @@ static struct security_operations selinux_ops = { .sb_free_security = selinux_sb_free_security, .sb_copy_data = selinux_sb_copy_data, .sb_kern_mount = selinux_sb_kern_mount, + .sb_show_options = selinux_sb_show_options, .sb_statfs = selinux_sb_statfs, .sb_mount = selinux_mount, .sb_umount = selinux_umount, - .sb_get_mnt_opts = selinux_get_mnt_opts, .sb_set_mnt_opts = selinux_set_mnt_opts, .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, .sb_parse_opts_str = selinux_parse_opts_str, @@ -5378,7 +5432,7 @@ static struct security_operations selinux_ops = { .inode_listsecurity = selinux_inode_listsecurity, .inode_need_killpriv = selinux_inode_need_killpriv, .inode_killpriv = selinux_inode_killpriv, - .inode_getsecid = selinux_inode_getsecid, + .inode_getsecid = selinux_inode_getsecid, .file_permission = selinux_file_permission, .file_alloc_security = selinux_file_alloc_security, @@ -5419,7 +5473,7 @@ static struct security_operations selinux_ops = { .task_to_inode = selinux_task_to_inode, .ipc_permission = selinux_ipc_permission, - .ipc_getsecid = selinux_ipc_getsecid, + .ipc_getsecid = selinux_ipc_getsecid, .msg_msg_alloc_security = selinux_msg_msg_alloc_security, .msg_msg_free_security = selinux_msg_msg_free_security, @@ -5443,8 +5497,6 @@ static struct security_operations selinux_ops = { .sem_semctl = selinux_sem_semctl, .sem_semop = selinux_sem_semop, - .register_security = selinux_register_security, - .d_instantiate = selinux_d_instantiate, .getprocattr = selinux_getprocattr, @@ -5538,7 +5590,7 @@ static __init int selinux_init(void) 0, SLAB_PANIC, NULL); avc_init(); - original_ops = secondary_ops = security_ops; + secondary_ops = security_ops; if (!secondary_ops) panic("SELinux: No initial security operations\n"); if (register_security(&selinux_ops)) |