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-rw-r--r--security/smack/Kconfig12
-rw-r--r--security/smack/smack.h10
-rw-r--r--security/smack/smack_lsm.c14
3 files changed, 29 insertions, 7 deletions
diff --git a/security/smack/Kconfig b/security/smack/Kconfig
index 271adae81796..923b120e0fa5 100644
--- a/security/smack/Kconfig
+++ b/security/smack/Kconfig
@@ -40,3 +40,15 @@ config SECURITY_SMACK_NETFILTER
This enables security marking of network packets using
Smack labels.
If you are unsure how to answer this question, answer N.
+
+config SECURITY_SMACK_APPEND_SIGNALS
+ bool "Treat delivering signals as an append operation"
+ depends on SECURITY_SMACK
+ default n
+ help
+ Sending a signal has been treated as a write operation to the
+ receiving process. If this option is selected, the delivery
+ will be an append operation instead. This makes it possible
+ to differentiate between delivering a network packet and
+ delivering a signal in the Smack rules.
+ If you are unsure how to answer this question, answer N.
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 26e58f1804b1..51fd30192c08 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -256,6 +256,16 @@ enum {
#define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */
#define MAY_BRINGUP 0x00004000 /* Report use of this rule */
+/*
+ * The policy for delivering signals is configurable.
+ * It is usually "write", but can be "append".
+ */
+#ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS
+#define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */
+#else
+#define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */
+#endif
+
#define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */
#define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */
#define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 87a9741b0d02..caec2256ab22 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1857,14 +1857,14 @@ static int smack_file_send_sigiotask(struct task_struct *tsk,
/* we don't log here as rc can be overriden */
skp = file->f_security;
- rc = smk_access(skp, tkp, MAY_WRITE, NULL);
- rc = smk_bu_note("sigiotask", skp, tkp, MAY_WRITE, rc);
+ rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
+ rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
rc = 0;
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, tsk);
- smack_log(skp->smk_known, tkp->smk_known, MAY_WRITE, rc, &ad);
+ smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
return rc;
}
@@ -2265,8 +2265,8 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info,
* can write the receiver.
*/
if (secid == 0) {
- rc = smk_curacc(tkp, MAY_WRITE, &ad);
- rc = smk_bu_task(p, MAY_WRITE, rc);
+ rc = smk_curacc(tkp, MAY_DELIVER, &ad);
+ rc = smk_bu_task(p, MAY_DELIVER, rc);
return rc;
}
/*
@@ -2275,8 +2275,8 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info,
* we can't take privilege into account.
*/
skp = smack_from_secid(secid);
- rc = smk_access(skp, tkp, MAY_WRITE, &ad);
- rc = smk_bu_note("USB signal", skp, tkp, MAY_WRITE, rc);
+ rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
+ rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
return rc;
}