diff options
author | John Johansen <john.johansen@canonical.com> | 2017-06-09 07:09:05 -0700 |
---|---|---|
committer | John Johansen <john.johansen@canonical.com> | 2017-06-10 17:11:35 -0700 |
commit | a1bd627b46d169268a0ee5960899fb5be960a317 (patch) | |
tree | ddcc330c5ddc6efb5e18f1943a55ce4e11884743 | |
parent | cf797c0e5e312520b0b9f0367039fc0279a07a76 (diff) | |
download | linux-a1bd627b46d169268a0ee5960899fb5be960a317.tar.gz linux-a1bd627b46d169268a0ee5960899fb5be960a317.tar.bz2 linux-a1bd627b46d169268a0ee5960899fb5be960a317.zip |
apparmor: share profile name on replacement
The profile names are the same, leverage this.
Signed-off-by: John Johansen <john.johansen@canonical.com>
-rw-r--r-- | security/apparmor/include/lib.h | 32 | ||||
-rw-r--r-- | security/apparmor/lib.c | 40 | ||||
-rw-r--r-- | security/apparmor/policy.c | 9 |
3 files changed, 72 insertions, 9 deletions
diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h index 89524aade657..593877d38088 100644 --- a/security/apparmor/include/lib.h +++ b/security/apparmor/include/lib.h @@ -100,6 +100,36 @@ static inline bool path_mediated_fs(struct dentry *dentry) return !(dentry->d_sb->s_flags & MS_NOUSER); } + +struct counted_str { + struct kref count; + char name[]; +}; + +#define str_to_counted(str) \ + ((struct counted_str *)(str - offsetof(struct counted_str, name))) + +#define __counted /* atm just a notation */ + +void aa_str_kref(struct kref *kref); +char *aa_str_alloc(int size, gfp_t gfp); + + +static inline __counted char *aa_get_str(__counted char *str) +{ + if (str) + kref_get(&(str_to_counted(str)->count)); + + return str; +} + +static inline void aa_put_str(__counted char *str) +{ + if (str) + kref_put(&str_to_counted(str)->count, aa_str_kref); +} + + /* struct aa_policy - common part of both namespaces and profiles * @name: name of the object * @hname - The hierarchical name @@ -108,7 +138,7 @@ static inline bool path_mediated_fs(struct dentry *dentry) */ struct aa_policy { const char *name; - const char *hname; + __counted char *hname; struct list_head list; struct list_head profiles; }; diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c index 3e9146e68c4a..0ceecdbb4658 100644 --- a/security/apparmor/lib.c +++ b/security/apparmor/lib.c @@ -134,6 +134,24 @@ void aa_info_message(const char *str) printk(KERN_INFO "AppArmor: %s\n", str); } +__counted char *aa_str_alloc(int size, gfp_t gfp) +{ + struct counted_str *str; + + str = kmalloc(sizeof(struct counted_str) + size, gfp); + if (!str) + return NULL; + + kref_init(&str->count); + return str->name; +} + +void aa_str_kref(struct kref *kref) +{ + kfree(container_of(kref, struct counted_str, count)); +} + + const char aa_file_perm_chrs[] = "xwracd km l "; const char *aa_file_perm_names[] = { "exec", @@ -296,6 +314,7 @@ void aa_compute_perms(struct aa_dfa *dfa, unsigned int state, * @policy: policy to initialize (NOT NULL) * @prefix: prefix name if any is required. (MAYBE NULL) * @name: name of the policy, init will make a copy of it (NOT NULL) + * @gfp: allocation mode * * Note: this fn creates a copy of strings passed in * @@ -304,16 +323,21 @@ void aa_compute_perms(struct aa_dfa *dfa, unsigned int state, bool aa_policy_init(struct aa_policy *policy, const char *prefix, const char *name, gfp_t gfp) { + char *hname; + /* freed by policy_free */ if (prefix) { - policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3, - gfp); - if (policy->hname) - sprintf((char *)policy->hname, "%s//%s", prefix, name); - } else - policy->hname = kstrdup(name, gfp); - if (!policy->hname) + hname = aa_str_alloc(strlen(prefix) + strlen(name) + 3, gfp); + if (hname) + sprintf(hname, "%s//%s", prefix, name); + } else { + hname = aa_str_alloc(strlen(name) + 1, gfp); + if (hname) + strcpy(hname, name); + } + if (!hname) return false; + policy->hname = hname; /* base.name is a substring of fqname */ policy->name = basename(policy->hname); INIT_LIST_HEAD(&policy->list); @@ -332,5 +356,5 @@ void aa_policy_destroy(struct aa_policy *policy) AA_BUG(on_list_rcu(&policy->list)); /* don't free name as its a subset of hname */ - kzfree(policy->hname); + aa_put_str(policy->hname); } diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index 29e04638790f..af925c07ad4e 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -829,6 +829,14 @@ static int __lookup_replace(struct aa_ns *ns, const char *hname, return 0; } +static void share_name(struct aa_profile *old, struct aa_profile *new) +{ + aa_put_str(new->base.hname); + aa_get_str(old->base.hname); + new->base.hname = old->base.hname; + new->base.name = old->base.name; +} + /** * aa_replace_profiles - replace profile(s) on the profile list * @policy_ns: namespace load is occurring on @@ -1013,6 +1021,7 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_profile *profile, NULL, error); if (ent->old) { + share_name(ent->old, ent->new); __replace_profile(ent->old, ent->new, 1); if (ent->rename) { /* aafs interface uses proxy */ |