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| author | Vishal Goel <vishal.goel@samsung.com> | 2016-11-23 10:46:57 +0530 |
|---|---|---|
| committer | Casey Schaufler <casey@schaufler-ca.com> | 2017-01-10 09:47:20 -0800 |
| commit | 2e962e2fec5c35b91e3b541e2b8373504bf91e27 (patch) | |
| tree | 60f9eec5feb6f7b45fe43f80f9ee81a5a22c4905 /security | |
| parent | 0c96d1f5328e834048480e4696e6867992115c33 (diff) | |
| download | linux-2e962e2fec5c35b91e3b541e2b8373504bf91e27.tar.gz linux-2e962e2fec5c35b91e3b541e2b8373504bf91e27.tar.bz2 linux-2e962e2fec5c35b91e3b541e2b8373504bf91e27.zip | |
SMACK: Add new lock for adding entry in smack master list
"smk_set_access()" function adds a new rule entry in subject label specific
list(rule_list) and in global rule list(smack_rule_list) both. Mutex lock
(rule_lock) is used to avoid simultaneous updates. But this lock is subject
label specific lock. If 2 processes tries to add different rules(i.e with
different subject labels) simultaneously, then both the processes can take
the "rule_lock" respectively. So it will cause a problem while adding
entries in master rule list.
Now a new mutex lock(smack_master_list_lock) has been taken to add entry in
smack_rule_list to avoid simultaneous updates of different rules.
Signed-off-by: Vishal Goel <vishal.goel@samsung.com>
Signed-off-by: Himanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/smack/smackfs.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 13743a01b35b..366b8356f75b 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -67,6 +67,7 @@ enum smk_inos { /* * List locks */ +static DEFINE_MUTEX(smack_master_list_lock); static DEFINE_MUTEX(smack_cipso_lock); static DEFINE_MUTEX(smack_ambient_lock); static DEFINE_MUTEX(smk_net4addr_lock); @@ -262,12 +263,16 @@ static int smk_set_access(struct smack_parsed_rule *srp, * it needs to get added for reporting. */ if (global) { + mutex_unlock(rule_lock); smlp = kzalloc(sizeof(*smlp), GFP_KERNEL); if (smlp != NULL) { smlp->smk_rule = sp; + mutex_lock(&smack_master_list_lock); list_add_rcu(&smlp->list, &smack_rule_list); + mutex_unlock(&smack_master_list_lock); } else rc = -ENOMEM; + return rc; } } |