From 8a6f83afd0c5355db6d11394a798e94950306239 Mon Sep 17 00:00:00 2001 From: KaiGai Kohei Date: Wed, 1 Apr 2009 10:07:57 +0900 Subject: Permissive domain in userspace object manager This patch enables applications to handle permissive domain correctly. Since the v2.6.26 kernel, SELinux has supported an idea of permissive domain which allows certain processes to work as if permissive mode, even if the global setting is enforcing mode. However, we don't have an application program interface to inform what domains are permissive one, and what domains are not. It means applications focuses on SELinux (XACE/SELinux, SE-PostgreSQL and so on) cannot handle permissive domain correctly. This patch add the sixth field (flags) on the reply of the /selinux/access interface which is used to make an access control decision from userspace. If the first bit of the flags field is positive, it means the required access control decision is on permissive domain, so application should allow any required actions, as the kernel doing. This patch also has a side benefit. The av_decision.flags is set at context_struct_compute_av(). It enables to check required permissions without read_lock(&policy_rwlock). Signed-off-by: KaiGai Kohei Acked-by: Stephen Smalley Acked-by: Eric Paris -- security/selinux/avc.c | 2 +- security/selinux/include/security.h | 4 +++- security/selinux/selinuxfs.c | 4 ++-- security/selinux/ss/services.c | 30 +++++------------------------- 4 files changed, 11 insertions(+), 29 deletions(-) Signed-off-by: James Morris --- security/selinux/avc.c | 2 +- security/selinux/include/security.h | 4 +++- security/selinux/selinuxfs.c | 4 ++-- security/selinux/ss/services.c | 30 +++++------------------------- 4 files changed, 11 insertions(+), 29 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 7f9b5fac8779..b2ab60859832 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -927,7 +927,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, if (denied) { if (flags & AVC_STRICT) rc = -EACCES; - else if (!selinux_enforcing || security_permissive_sid(ssid)) + else if (!selinux_enforcing || (avd->flags & AVD_FLAGS_PERMISSIVE)) avc_update_node(AVC_CALLBACK_GRANT, requested, ssid, tsid, tclass, avd->seqno); else diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index 5c3434f7626f..a7be3f01fb08 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -91,9 +91,11 @@ struct av_decision { u32 auditallow; u32 auditdeny; u32 seqno; + u32 flags; }; -int security_permissive_sid(u32 sid); +/* definitions of av_decision.flags */ +#define AVD_FLAGS_PERMISSIVE 0x0001 int security_compute_av(u32 ssid, u32 tsid, u16 tclass, u32 requested, diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 2d5136ec3d54..8d4007fbe0e9 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -527,10 +527,10 @@ static ssize_t sel_write_access(struct file *file, char *buf, size_t size) goto out2; length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT, - "%x %x %x %x %u", + "%x %x %x %x %u %x", avd.allowed, 0xffffffff, avd.auditallow, avd.auditdeny, - avd.seqno); + avd.seqno, avd.flags); out2: kfree(tcon); out: diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index deeec6c013ae..500e6f78e115 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -410,6 +410,7 @@ static int context_struct_compute_av(struct context *scontext, avd->auditallow = 0; avd->auditdeny = 0xffffffff; avd->seqno = latest_granting; + avd->flags = 0; /* * Check for all the invalid cases. @@ -528,31 +529,6 @@ inval_class: return 0; } -/* - * Given a sid find if the type has the permissive flag set - */ -int security_permissive_sid(u32 sid) -{ - struct context *context; - u32 type; - int rc; - - read_lock(&policy_rwlock); - - context = sidtab_search(&sidtab, sid); - BUG_ON(!context); - - type = context->type; - /* - * we are intentionally using type here, not type-1, the 0th bit may - * someday indicate that we are globally setting permissive in policy. - */ - rc = ebitmap_get_bit(&policydb.permissive_map, type); - - read_unlock(&policy_rwlock); - return rc; -} - static int security_validtrans_handle_fail(struct context *ocontext, struct context *ncontext, struct context *tcontext, @@ -767,6 +743,10 @@ int security_compute_av(u32 ssid, rc = context_struct_compute_av(scontext, tcontext, tclass, requested, avd); + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb.permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; out: read_unlock(&policy_rwlock); return rc; -- cgit v1.2.1 From 88c48db9788862d0290831d081bc3c64e13b592f Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 29 Apr 2009 14:00:25 -0400 Subject: SELinux: drop secondary_ops->sysctl We are still calling secondary_ops->sysctl even though the capabilities module does not define a sysctl operation. Signed-off-by: Eric Paris Acked-by: Stephen Smalley Signed-off-by: James Morris --- security/selinux/hooks.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ba808ef6babb..dd19ba81201f 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1980,10 +1980,6 @@ static int selinux_sysctl(ctl_table *table, int op) u32 tsid, sid; int rc; - rc = secondary_ops->sysctl(table, op); - if (rc) - return rc; - sid = current_sid(); rc = selinux_sysctl_get_sid(table, (op == 0001) ? -- cgit v1.2.1 From 3bcac0263f0b45e67a64034ebcb69eb9abb742f4 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 29 Apr 2009 13:45:05 +0100 Subject: SELinux: Don't flush inherited SIGKILL during execve() Don't flush inherited SIGKILL during execve() in SELinux's post cred commit hook. This isn't really a security problem: if the SIGKILL came before the credentials were changed, then we were right to receive it at the time, and should honour it; if it came after the creds were changed, then we definitely should honour it; and in any case, all that will happen is that the process will be scrapped before it ever returns to userspace. Signed-off-by: David Howells Signed-off-by: Oleg Nesterov Signed-off-by: James Morris --- security/selinux/hooks.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index dd19ba81201f..5a345115036c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2394,11 +2394,12 @@ static void selinux_bprm_committed_creds(struct linux_binprm *bprm) memset(&itimer, 0, sizeof itimer); for (i = 0; i < 3; i++) do_setitimer(i, &itimer, NULL); - flush_signals(current); spin_lock_irq(¤t->sighand->siglock); - flush_signal_handlers(current, 1); - sigemptyset(¤t->blocked); - recalc_sigpending(); + if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { + __flush_signals(current); + flush_signal_handlers(current, 1); + sigemptyset(¤t->blocked); + } spin_unlock_irq(¤t->sighand->siglock); } -- cgit v1.2.1 From ecd6de3c88e8cbcad175b2eab48ba05c2014f7b6 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 29 Apr 2009 16:02:24 +0200 Subject: selinux: selinux_bprm_committed_creds() should wake up ->real_parent, not ->parent. We shouldn't worry about the tracer if current is ptraced, exec() must not succeed if the tracer has no rights to trace this task after cred changing. But we should notify ->real_parent which is, well, real parent. Also, we don't need _irq to take tasklist, and we don't need parent's ->siglock to wake_up_interruptible(real_parent->signal->wait_chldexit). Since we hold tasklist, real_parent->signal must be stable. Otherwise spin_lock(siglock) is not safe too and can't help anyway. Signed-off-by: Oleg Nesterov Signed-off-by: James Morris --- security/selinux/hooks.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 5a345115036c..39046ddd90a9 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2371,10 +2371,8 @@ static void selinux_bprm_committed_creds(struct linux_binprm *bprm) { const struct task_security_struct *tsec = current_security(); struct itimerval itimer; - struct sighand_struct *psig; u32 osid, sid; int rc, i; - unsigned long flags; osid = tsec->osid; sid = tsec->sid; @@ -2405,12 +2403,9 @@ static void selinux_bprm_committed_creds(struct linux_binprm *bprm) /* Wake up the parent if it is waiting so that it can recheck * wait permission to the new task SID. */ - read_lock_irq(&tasklist_lock); - psig = current->parent->sighand; - spin_lock_irqsave(&psig->siglock, flags); - wake_up_interruptible(¤t->parent->signal->wait_chldexit); - spin_unlock_irqrestore(&psig->siglock, flags); - read_unlock_irq(&tasklist_lock); + read_lock(&tasklist_lock); + wake_up_interruptible(¤t->real_parent->signal->wait_chldexit); + read_unlock(&tasklist_lock); } /* superblock security operations */ -- cgit v1.2.1 From 75834fc3b6fcff00327f5d2a18760c1e8e0179c5 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Mon, 18 May 2009 10:26:10 -0400 Subject: SELinux: move SELINUX_MAGIC into magic.h The selinuxfs superblock magic is used inside the IMA code, but is being defined in two places and could someday get out of sync. This patch moves the declaration into magic.h so it is only done once. Signed-off-by: Eric Paris Signed-off-by: James Morris --- security/selinux/include/security.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index a7be3f01fb08..ca835795a8b3 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -8,14 +8,13 @@ #ifndef _SELINUX_SECURITY_H_ #define _SELINUX_SECURITY_H_ +#include #include "flask.h" #define SECSID_NULL 0x00000000 /* unspecified SID */ #define SECSID_WILD 0xffffffff /* wildcard SID */ #define SECCLASS_NULL 0x0000 /* no class */ -#define SELINUX_MAGIC 0xf97cff8c - /* Identify specific policy version changes */ #define POLICYDB_VERSION_BASE 15 #define POLICYDB_VERSION_BOOL 16 -- cgit v1.2.1 From c5642f4bbae30122beb696e723f6da273caa570e Mon Sep 17 00:00:00 2001 From: Stephen Smalley Date: Tue, 19 May 2009 09:02:23 -0400 Subject: selinux: remove obsolete read buffer limit from sel_read_bool On Tue, 2009-05-19 at 00:05 -0400, Eamon Walsh wrote: > Recent versions of coreutils have bumped the read buffer size from 4K to > 32K in several of the utilities. > > This means that "cat /selinux/booleans/xserver_object_manager" no longer > works, it returns "Invalid argument" on F11. getsebool works fine. > > sel_read_bool has a check for "count > PAGE_SIZE" that doesn't seem to > be present in the other read functions. Maybe it could be removed? Yes, that check is obsoleted by the conversion of those functions to using simple_read_from_buffer(), which will reduce count if necessary to what is available in the buffer. Signed-off-by: Stephen Smalley Signed-off-by: James Morris --- security/selinux/selinuxfs.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 8d4007fbe0e9..b4fc506e7a87 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -803,10 +803,6 @@ static ssize_t sel_read_bool(struct file *filep, char __user *buf, goto out; } - if (count > PAGE_SIZE) { - ret = -EINVAL; - goto out; - } page = (char *)get_zeroed_page(GFP_KERNEL); if (!page) { ret = -ENOMEM; -- cgit v1.2.1 From 850b0cee165576f969363a8c52021b5cf9ecbe67 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 2 Jun 2009 17:01:16 -0400 Subject: SELinux: define audit permissions for audit tree netlink messages Audit trees defined 2 new netlink messages but the netlink mapping tables for selinux permissions were not set up. This patch maps these 2 new operations to AUDIT_WRITE. Signed-off-by: Eric Paris Signed-off-by: James Morris --- security/selinux/nlmsgtab.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'security/selinux') diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c index c6875fd3b9d6..dd7cc6de77f9 100644 --- a/security/selinux/nlmsgtab.c +++ b/security/selinux/nlmsgtab.c @@ -112,6 +112,8 @@ static struct nlmsg_perm nlmsg_audit_perms[] = { AUDIT_DEL_RULE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, { AUDIT_USER, NETLINK_AUDIT_SOCKET__NLMSG_RELAY }, { AUDIT_SIGNAL_INFO, NETLINK_AUDIT_SOCKET__NLMSG_READ }, + { AUDIT_TRIM, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, + { AUDIT_MAKE_EQUIV, NETLINK_AUDIT_SOCKET__NLMSG_WRITE }, { AUDIT_TTY_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ }, { AUDIT_TTY_SET, NETLINK_AUDIT_SOCKET__NLMSG_TTY_AUDIT }, }; -- cgit v1.2.1