TOMOYO: Use mutex_lock_interruptible.

Some of TOMOYO's functions may sleep after mutex_lock(). If OOM-killer selected
a process which is waiting at mutex_lock(), the to-be-killed process can't be
killed. Thus, replace mutex_lock() with mutex_lock_interruptible() so that the
to-be-killed process can immediately return from TOMOYO's functions.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index e1edec4a9b9d..a1723bbcde0e 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -154,7 +154,8 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
                 goto out;
         if (!is_delete)
                 entry = kmalloc(sizeof(*entry), GFP_NOFS);
-        mutex_lock(&tomoyo_policy_lock);
+        if (mutex_lock_interruptible(&tomoyo_policy_lock))
+                goto out;
         list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list, list) {
                 if (ptr->is_not != is_not ||
                     ptr->domainname != saved_domainname ||
@@ -374,7 +375,8 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname,
                 goto out;
         if (!is_delete)
                 entry = kmalloc(sizeof(*entry), GFP_NOFS);
-        mutex_lock(&tomoyo_policy_lock);
+        if (mutex_lock_interruptible(&tomoyo_policy_lock))
+                goto out;
         list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) {
                 if (ptr->is_not != is_not ||
                     ptr->domainname != saved_domainname ||
@@ -566,7 +568,8 @@ static int tomoyo_update_alias_entry(const char *original_name,
                 goto out;
         if (!is_delete)
                 entry = kmalloc(sizeof(*entry), GFP_NOFS);
-        mutex_lock(&tomoyo_policy_lock);
+        if (mutex_lock_interruptible(&tomoyo_policy_lock))
+                goto out;
         list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) {
                 if (ptr->original_name != saved_original_name ||
                     ptr->aliased_name != saved_aliased_name)
@@ -656,7 +659,7 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
                                                             const u8 profile)
 {
         struct tomoyo_domain_info *entry;
-        struct tomoyo_domain_info *domain;
+        struct tomoyo_domain_info *domain = NULL;
         const struct tomoyo_path_info *saved_domainname;
         bool found = false;
 
@@ -666,7 +669,8 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
         if (!saved_domainname)
                 return NULL;
         entry = kzalloc(sizeof(*entry), GFP_NOFS);
-        mutex_lock(&tomoyo_policy_lock);
+        if (mutex_lock_interruptible(&tomoyo_policy_lock))
+                goto out;
         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
                 if (domain->is_deleted ||
                     tomoyo_pathcmp(saved_domainname, domain->domainname))
@@ -685,6 +689,7 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
                 found = true;
         }
         mutex_unlock(&tomoyo_policy_lock);
+ out:
         tomoyo_put_name(saved_domainname);
         kfree(entry);
         return found ? domain : NULL;