diff options
| -rw-r--r-- | security/device_cgroup.c | 198 |
1 files changed, 99 insertions, 99 deletions
diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 91cf803..44dfc41 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -26,12 +26,12 @@ static DEFINE_MUTEX(devcgroup_mutex); /* - * whitelist locking rules: + * exception list locking rules: * hold devcgroup_mutex for update/read. * hold rcu_read_lock() for read. */ -struct dev_whitelist_item { +struct dev_exception_item { u32 major, minor; short type; short access; @@ -41,7 +41,7 @@ struct dev_whitelist_item { struct dev_cgroup { struct cgroup_subsys_state css; - struct list_head whitelist; + struct list_head exceptions; bool deny_all; }; @@ -75,12 +75,12 @@ static int devcgroup_can_attach(struct cgroup *new_cgrp, /* * called under devcgroup_mutex */ -static int dev_whitelist_copy(struct list_head *dest, struct list_head *orig) +static int dev_exceptions_copy(struct list_head *dest, struct list_head *orig) { - struct dev_whitelist_item *wh, *tmp, *new; + struct dev_exception_item *ex, *tmp, *new; - list_for_each_entry(wh, orig, list) { - new = kmemdup(wh, sizeof(*wh), GFP_KERNEL); + list_for_each_entry(ex, orig, list) { + new = kmemdup(ex, sizeof(*ex), GFP_KERNEL); if (!new) goto free_and_exit; list_add_tail(&new->list, dest); @@ -89,9 +89,9 @@ static int dev_whitelist_copy(struct list_head *dest, struct list_head *orig) return 0; free_and_exit: - list_for_each_entry_safe(wh, tmp, dest, list) { - list_del(&wh->list); - kfree(wh); + list_for_each_entry_safe(ex, tmp, dest, list) { + list_del(&ex->list); + kfree(ex); } return -ENOMEM; } @@ -99,50 +99,50 @@ free_and_exit: /* * called under devcgroup_mutex */ -static int dev_whitelist_add(struct dev_cgroup *dev_cgroup, - struct dev_whitelist_item *wh) +static int dev_exception_add(struct dev_cgroup *dev_cgroup, + struct dev_exception_item *ex) { - struct dev_whitelist_item *whcopy, *walk; + struct dev_exception_item *excopy, *walk; - whcopy = kmemdup(wh, sizeof(*wh), GFP_KERNEL); - if (!whcopy) + excopy = kmemdup(ex, sizeof(*ex), GFP_KERNEL); + if (!excopy) return -ENOMEM; - list_for_each_entry(walk, &dev_cgroup->whitelist, list) { - if (walk->type != wh->type) + list_for_each_entry(walk, &dev_cgroup->exceptions, list) { + if (walk->type != ex->type) continue; - if (walk->major != wh->major) + if (walk->major != ex->major) continue; - if (walk->minor != wh->minor) + if (walk->minor != ex->minor) continue; - walk->access |= wh->access; - kfree(whcopy); - whcopy = NULL; + walk->access |= ex->access; + kfree(excopy); + excopy = NULL; } - if (whcopy != NULL) - list_add_tail_rcu(&whcopy->list, &dev_cgroup->whitelist); + if (excopy != NULL) + list_add_tail_rcu(&excopy->list, &dev_cgroup->exceptions); return 0; } /* * called under devcgroup_mutex */ -static void dev_whitelist_rm(struct dev_cgroup *dev_cgroup, - struct dev_whitelist_item *wh) +static void dev_exception_rm(struct dev_cgroup *dev_cgroup, + struct dev_exception_item *ex) { - struct dev_whitelist_item *walk, *tmp; + struct dev_exception_item *walk, *tmp; - list_for_each_entry_safe(walk, tmp, &dev_cgroup->whitelist, list) { - if (walk->type != wh->type) + list_for_each_entry_safe(walk, tmp, &dev_cgroup->exceptions, list) { + if (walk->type != ex->type) continue; - if (walk->major != wh->major) + if (walk->major != ex->major) continue; - if (walk->minor != wh->minor) + if (walk->minor != ex->minor) continue; - walk->access &= ~wh->access; + walk->access &= ~ex->access; if (!walk->access) { list_del_rcu(&walk->list); kfree_rcu(walk, rcu); @@ -151,18 +151,18 @@ static void dev_whitelist_rm(struct dev_cgroup *dev_cgroup, } /** - * dev_whitelist_clean - frees all entries of the whitelist - * @dev_cgroup: dev_cgroup with the whitelist to be cleaned + * dev_exception_clean - frees all entries of the exception list + * @dev_cgroup: dev_cgroup with the exception list to be cleaned * * called under devcgroup_mutex */ -static void dev_whitelist_clean(struct dev_cgroup *dev_cgroup) +static void dev_exception_clean(struct dev_cgroup *dev_cgroup) { - struct dev_whitelist_item *wh, *tmp; + struct dev_exception_item *ex, *tmp; - list_for_each_entry_safe(wh, tmp, &dev_cgroup->whitelist, list) { - list_del(&wh->list); - kfree(wh); + list_for_each_entry_safe(ex, tmp, &dev_cgroup->exceptions, list) { + list_del(&ex->list); + kfree(ex); } } @@ -178,7 +178,7 @@ static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup) dev_cgroup = kzalloc(sizeof(*dev_cgroup), GFP_KERNEL); if (!dev_cgroup) return ERR_PTR(-ENOMEM); - INIT_LIST_HEAD(&dev_cgroup->whitelist); + INIT_LIST_HEAD(&dev_cgroup->exceptions); parent_cgroup = cgroup->parent; if (parent_cgroup == NULL) @@ -186,8 +186,8 @@ static struct cgroup_subsys_state *devcgroup_create(struct cgroup *cgroup) else { parent_dev_cgroup = cgroup_to_devcgroup(parent_cgroup); mutex_lock(&devcgroup_mutex); - ret = dev_whitelist_copy(&dev_cgroup->whitelist, - &parent_dev_cgroup->whitelist); + ret = dev_exceptions_copy(&dev_cgroup->exceptions, + &parent_dev_cgroup->exceptions); dev_cgroup->deny_all = parent_dev_cgroup->deny_all; mutex_unlock(&devcgroup_mutex); if (ret) { @@ -204,7 +204,7 @@ static void devcgroup_destroy(struct cgroup *cgroup) struct dev_cgroup *dev_cgroup; dev_cgroup = cgroup_to_devcgroup(cgroup); - dev_whitelist_clean(dev_cgroup); + dev_exception_clean(dev_cgroup); kfree(dev_cgroup); } @@ -250,7 +250,7 @@ static int devcgroup_seq_read(struct cgroup *cgroup, struct cftype *cft, struct seq_file *m) { struct dev_cgroup *devcgroup = cgroup_to_devcgroup(cgroup); - struct dev_whitelist_item *wh; + struct dev_exception_item *ex; char maj[MAJMINLEN], min[MAJMINLEN], acc[ACCLEN]; rcu_read_lock(); @@ -267,11 +267,11 @@ static int devcgroup_seq_read(struct cgroup *cgroup, struct cftype *cft, seq_printf(m, "%c %s:%s %s\n", type_to_char(DEV_ALL), maj, min, acc); } else { - list_for_each_entry_rcu(wh, &devcgroup->whitelist, list) { - set_access(acc, wh->access); - set_majmin(maj, wh->major); - set_majmin(min, wh->minor); - seq_printf(m, "%c %s:%s %s\n", type_to_char(wh->type), + list_for_each_entry_rcu(ex, &devcgroup->exceptions, list) { + set_access(acc, ex->access); + set_majmin(maj, ex->major); + set_majmin(min, ex->minor); + seq_printf(m, "%c %s:%s %s\n", type_to_char(ex->type), maj, min, acc); } } @@ -281,42 +281,42 @@ static int devcgroup_seq_read(struct cgroup *cgroup, struct cftype *cft, } /** - * may_access_whitelist - verifies if a new rule is part of what is allowed - * by a dev cgroup based on the default policy + - * exceptions. This is used to make sure a child cgroup - * won't have more privileges than its parent or to - * verify if a certain access is allowed. + * may_access - verifies if a new exception is part of what is allowed + * by a dev cgroup based on the default policy + + * exceptions. This is used to make sure a child cgroup + * won't have more privileges than its parent or to + * verify if a certain access is allowed. * @dev_cgroup: dev cgroup to be tested against - * @refwh: new rule + * @refex: new exception */ -static int may_access_whitelist(struct dev_cgroup *dev_cgroup, - struct dev_whitelist_item *refwh) +static int may_access(struct dev_cgroup *dev_cgroup, + struct dev_exception_item *refex) { - struct dev_whitelist_item *whitem; + struct dev_exception_item *ex; bool match = false; - list_for_each_entry(whitem, &dev_cgroup->whitelist, list) { - if ((refwh->type & DEV_BLOCK) && !(whitem->type & DEV_BLOCK)) + list_for_each_entry(ex, &dev_cgroup->exceptions, list) { + if ((refex->type & DEV_BLOCK) && !(ex->type & DEV_BLOCK)) continue; - if ((refwh->type & DEV_CHAR) && !(whitem->type & DEV_CHAR)) + if ((refex->type & DEV_CHAR) && !(ex->type & DEV_CHAR)) continue; - if (whitem->major != ~0 && whitem->major != refwh->major) + if (ex->major != ~0 && ex->major != refex->major) continue; - if (whitem->minor != ~0 && whitem->minor != refwh->minor) + if (ex->minor != ~0 && ex->minor != refex->minor) continue; - if (refwh->access & (~whitem->access)) + if (refex->access & (~ex->access)) continue; match = true; break; } /* - * In two cases we'll consider this new rule valid: + * In two cases we'll consider this new exception valid: * - the dev cgroup has its default policy to allow + exception list: - * the new rule should *not* match any of the exceptions + * the new exception should *not* match any of the exceptions * (!deny_all, !match) * - the dev cgroup has its default policy to deny + exception list: - * the new rule *should* match the exceptions + * the new exception *should* match the exceptions * (deny_all, match) */ if (dev_cgroup->deny_all == match) @@ -326,11 +326,11 @@ static int may_access_whitelist(struct dev_cgroup *dev_cgroup, /* * parent_has_perm: - * when adding a new allow rule to a device whitelist, the rule + * when adding a new allow rule to a device exception list, the rule * must be allowed in the parent device */ static int parent_has_perm(struct dev_cgroup *childcg, - struct dev_whitelist_item *wh) + struct dev_exception_item *ex) { struct cgroup *pcg = childcg->css.cgroup->parent; struct dev_cgroup *parent; @@ -338,17 +338,17 @@ static int parent_has_perm(struct dev_cgroup *childcg, if (!pcg) return 1; parent = cgroup_to_devcgroup(pcg); - return may_access_whitelist(parent, wh); + return may_access(parent, ex); } /* - * Modify the whitelist using allow/deny rules. + * Modify the exception list using allow/deny rules. * CAP_SYS_ADMIN is needed for this. It's at least separate from CAP_MKNOD * so we can give a container CAP_MKNOD to let it create devices but not - * modify the whitelist. + * modify the exception list. * It seems likely we'll want to add a CAP_CONTAINER capability to allow * us to also grant CAP_SYS_ADMIN to containers without giving away the - * device whitelist controls, but for now we'll stick with CAP_SYS_ADMIN + * device exception list controls, but for now we'll stick with CAP_SYS_ADMIN * * Taking rules away is always allowed (given CAP_SYS_ADMIN). Granting * new access is only allowed if you're in the top-level cgroup, or your @@ -360,25 +360,25 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, const char *b; char *endp; int count; - struct dev_whitelist_item wh; + struct dev_exception_item ex; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - memset(&wh, 0, sizeof(wh)); + memset(&ex, 0, sizeof(ex)); b = buffer; switch (*b) { case 'a': switch (filetype) { case DEVCG_ALLOW: - if (!parent_has_perm(devcgroup, &wh)) + if (!parent_has_perm(devcgroup, &ex)) return -EPERM; - dev_whitelist_clean(devcgroup); + dev_exception_clean(devcgroup); devcgroup->deny_all = false; break; case DEVCG_DENY: - dev_whitelist_clean(devcgroup); + dev_exception_clean(devcgroup); devcgroup->deny_all = true; break; default: @@ -386,10 +386,10 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, } return 0; case 'b': - wh.type = DEV_BLOCK; + ex.type = DEV_BLOCK; break; case 'c': - wh.type = DEV_CHAR; + ex.type = DEV_CHAR; break; default: return -EINVAL; @@ -399,10 +399,10 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, return -EINVAL; b++; if (*b == '*') { - wh.major = ~0; + ex.major = ~0; b++; } else if (isdigit(*b)) { - wh.major = simple_strtoul(b, &endp, 10); + ex.major = simple_strtoul(b, &endp, 10); b = endp; } else { return -EINVAL; @@ -413,10 +413,10 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, /* read minor */ if (*b == '*') { - wh.minor = ~0; + ex.minor = ~0; b++; } else if (isdigit(*b)) { - wh.minor = simple_strtoul(b, &endp, 10); + ex.minor = simple_strtoul(b, &endp, 10); b = endp; } else { return -EINVAL; @@ -426,13 +426,13 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, for (b++, count = 0; count < 3; count++, b++) { switch (*b) { case 'r': - wh.access |= ACC_READ; + ex.access |= ACC_READ; break; case 'w': - wh.access |= ACC_WRITE; + ex.access |= ACC_WRITE; break; case 'm': - wh.access |= ACC_MKNOD; + ex.access |= ACC_MKNOD; break; case '\n': case '\0': @@ -445,7 +445,7 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, switch (filetype) { case DEVCG_ALLOW: - if (!parent_has_perm(devcgroup, &wh)) + if (!parent_has_perm(devcgroup, &ex)) return -EPERM; /* * If the default policy is to allow by default, try to remove @@ -453,10 +453,10 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, * don't want to break compatibility */ if (devcgroup->deny_all == false) { - dev_whitelist_rm(devcgroup, &wh); + dev_exception_rm(devcgroup, &ex); return 0; } - return dev_whitelist_add(devcgroup, &wh); + return dev_exception_add(devcgroup, &ex); case DEVCG_DENY: /* * If the default policy is to deny by default, try to remove @@ -464,10 +464,10 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup, * don't want to break compatibility */ if (devcgroup->deny_all == true) { - dev_whitelist_rm(devcgroup, &wh); + dev_exception_rm(devcgroup, &ex); return 0; } - return dev_whitelist_add(devcgroup, &wh); + return dev_exception_add(devcgroup, &ex); default: return -EINVAL; } @@ -537,17 +537,17 @@ static int __devcgroup_check_permission(struct dev_cgroup *dev_cgroup, short type, u32 major, u32 minor, short access) { - struct dev_whitelist_item wh; + struct dev_exception_item ex; int rc; - memset(&wh, 0, sizeof(wh)); - wh.type = type; - wh.major = major; - wh.minor = minor; - wh.access = access; + memset(&ex, 0, sizeof(ex)); + ex.type = type; + ex.major = major; + ex.minor = minor; + ex.access = access; rcu_read_lock(); - rc = may_access_whitelist(dev_cgroup, &wh); + rc = may_access(dev_cgroup, &ex); rcu_read_unlock(); if (!rc) |