X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=security%2Fcommoncap.c;h=ea61bc73f6d3c4d1ecfe9d81964342b8cd306d74;hb=9ebbec27da6d7f4762b73985ac4929acf061d48b;hp=48ca5b092768fdde28e1df98b6420e47af0e82b1;hpb=ab08ed1770140ebcf1be1657087689832b755874;p=linux-2.6-omap-h63xx.git

diff --git a/security/commoncap.c b/security/commoncap.c
index 48ca5b09276..ea61bc73f6d 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -23,6 +23,7 @@
 #include <linux/xattr.h>
 #include <linux/hugetlb.h>
 #include <linux/mount.h>
+#include <linux/sched.h>
 
 #ifdef CONFIG_SECURITY_FILE_CAPABILITIES
 /*
@@ -58,6 +59,12 @@ int cap_netlink_recv(struct sk_buff *skb, int cap)
 
 EXPORT_SYMBOL(cap_netlink_recv);
 
+/*
+ * NOTE WELL: cap_capable() cannot be used like the kernel's capable()
+ * function.  That is, it has the reverse semantics: cap_capable()
+ * returns 0 when a task has a capability, but the kernel's capable()
+ * returns 1 for this case.
+ */
 int cap_capable (struct task_struct *tsk, int cap)
 {
 	/* Derived from include/linux/sched.h:capable. */
@@ -106,10 +113,11 @@ static inline int cap_block_setpcap(struct task_struct *target)
 static inline int cap_inh_is_capped(void)
 {
 	/*
-	 * return 1 if changes to the inheritable set are limited
-	 * to the old permitted set.
+	 * Return 1 if changes to the inheritable set are limited
+	 * to the old permitted set. That is, if the current task
+	 * does *not* possess the CAP_SETPCAP capability.
 	 */
-	return !cap_capable(current, CAP_SETPCAP);
+	return (cap_capable(current, CAP_SETPCAP) != 0);
 }
 
 #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */
@@ -189,7 +197,8 @@ int cap_inode_killpriv(struct dentry *dentry)
 	return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
 }
 
-static inline int cap_from_disk(__le32 *caps, struct linux_binprm *bprm,
+static inline int cap_from_disk(struct vfs_cap_data *caps,
+				struct linux_binprm *bprm,
 				int size)
 {
 	__u32 magic_etc;
@@ -197,7 +206,7 @@ static inline int cap_from_disk(__le32 *caps, struct linux_binprm *bprm,
 	if (size != XATTR_CAPS_SZ)
 		return -EINVAL;
 
-	magic_etc = le32_to_cpu(caps[0]);
+	magic_etc = le32_to_cpu(caps->magic_etc);
 
 	switch ((magic_etc & VFS_CAP_REVISION_MASK)) {
 	case VFS_CAP_REVISION:
@@ -205,8 +214,8 @@ static inline int cap_from_disk(__le32 *caps, struct linux_binprm *bprm,
 			bprm->cap_effective = true;
 		else
 			bprm->cap_effective = false;
-		bprm->cap_permitted = to_cap_t( le32_to_cpu(caps[1]) );
-		bprm->cap_inheritable = to_cap_t( le32_to_cpu(caps[2]) );
+		bprm->cap_permitted = to_cap_t(le32_to_cpu(caps->permitted));
+		bprm->cap_inheritable = to_cap_t(le32_to_cpu(caps->inheritable));
 		return 0;
 	default:
 		return -EINVAL;
@@ -218,7 +227,7 @@ static int get_file_caps(struct linux_binprm *bprm)
 {
 	struct dentry *dentry;
 	int rc = 0;
-	__le32 v1caps[XATTR_CAPS_SZ];
+	struct vfs_cap_data incaps;
 	struct inode *inode;
 
 	if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) {
@@ -231,8 +240,14 @@ static int get_file_caps(struct linux_binprm *bprm)
 	if (!inode->i_op || !inode->i_op->getxattr)
 		goto out;
 
-	rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &v1caps,
-							XATTR_CAPS_SZ);
+	rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0);
+	if (rc > 0) {
+		if (rc == XATTR_CAPS_SZ)
+			rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS,
+						&incaps, XATTR_CAPS_SZ);
+		else
+			rc = -EINVAL;
+	}
 	if (rc == -ENODATA || rc == -EOPNOTSUPP) {
 		/* no data, that's ok */
 		rc = 0;
@@ -241,7 +256,7 @@ static int get_file_caps(struct linux_binprm *bprm)
 	if (rc < 0)
 		goto out;
 
-	rc = cap_from_disk(v1caps, bprm, rc);
+	rc = cap_from_disk(&incaps, bprm, rc);
 	if (rc)
 		printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
 			__FUNCTION__, rc, bprm->filename);
@@ -334,7 +349,7 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
 	/* For init, we want to retain the capabilities set
 	 * in the init_task struct. Thus we skip the usual
 	 * capability rules */
-	if (!is_init(current)) {
+	if (!is_global_init(current)) {
 		current->cap_permitted = new_permitted;
 		current->cap_effective = bprm->cap_effective ?
 				new_permitted : 0;
@@ -518,6 +533,19 @@ int cap_task_kill(struct task_struct *p, struct siginfo *info,
 	if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
 		return 0;
 
+	/*
+	 * Running a setuid root program raises your capabilities.
+	 * Killing your own setuid root processes was previously
+	 * allowed.
+	 * We must preserve legacy signal behavior in this case.
+	 */
+	if (p->euid == 0 && p->uid == current->uid)
+		return 0;
+
+	/* sigcont is permitted within same session */
+	if (sig == SIGCONT && (task_session_nr(current) == task_session_nr(p)))
+		return 0;
+
 	if (secid)
 		/*
 		 * Signal sent as a particular user.