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@@ -169,19 +169,10 @@ void putname(const char *name)
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EXPORT_SYMBOL(putname);
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#endif
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-
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-/**
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- * generic_permission - check for access rights on a Posix-like filesystem
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- * @inode: inode to check access rights for
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- * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
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- * @check_acl: optional callback to check for Posix ACLs
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- *
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- * Used to check for read/write/execute permissions on a file.
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- * We use "fsuid" for this, letting us set arbitrary permissions
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- * for filesystem access without changing the "normal" uids which
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- * are used for other things..
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+/*
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+ * This does basic POSIX ACL permission checking
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*/
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-int generic_permission(struct inode *inode, int mask,
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+static int acl_permission_check(struct inode *inode, int mask,
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int (*check_acl)(struct inode *inode, int mask))
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{
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umode_t mode = inode->i_mode;
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@@ -193,9 +184,7 @@ int generic_permission(struct inode *inode, int mask,
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else {
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if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
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int error = check_acl(inode, mask);
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- if (error == -EACCES)
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- goto check_capabilities;
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- else if (error != -EAGAIN)
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+ if (error != -EAGAIN)
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return error;
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}
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@@ -208,8 +197,32 @@ int generic_permission(struct inode *inode, int mask,
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*/
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if ((mask & ~mode) == 0)
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return 0;
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+ return -EACCES;
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+}
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+
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+/**
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+ * generic_permission - check for access rights on a Posix-like filesystem
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+ * @inode: inode to check access rights for
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+ * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
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+ * @check_acl: optional callback to check for Posix ACLs
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+ *
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+ * Used to check for read/write/execute permissions on a file.
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+ * We use "fsuid" for this, letting us set arbitrary permissions
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+ * for filesystem access without changing the "normal" uids which
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+ * are used for other things..
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+ */
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+int generic_permission(struct inode *inode, int mask,
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+ int (*check_acl)(struct inode *inode, int mask))
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+{
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+ int ret;
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+
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+ /*
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+ * Do the basic POSIX ACL permission checks.
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+ */
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+ ret = acl_permission_check(inode, mask, check_acl);
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+ if (ret != -EACCES)
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+ return ret;
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- check_capabilities:
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/*
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* Read/write DACs are always overridable.
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* Executable DACs are overridable if at least one exec bit is set.
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@@ -262,7 +275,7 @@ int inode_permission(struct inode *inode, int mask)
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if (inode->i_op->permission)
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retval = inode->i_op->permission(inode, mask);
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else
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- retval = generic_permission(inode, mask, NULL);
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+ retval = generic_permission(inode, mask, inode->i_op->check_acl);
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if (retval)
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return retval;
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@@ -432,29 +445,22 @@ static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name,
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*/
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static int exec_permission_lite(struct inode *inode)
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{
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- umode_t mode = inode->i_mode;
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-
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- if (inode->i_op->permission)
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- return -EAGAIN;
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-
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- if (current_fsuid() == inode->i_uid)
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- mode >>= 6;
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- else if (in_group_p(inode->i_gid))
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- mode >>= 3;
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-
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- if (mode & MAY_EXEC)
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- goto ok;
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+ int ret;
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- if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE))
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- goto ok;
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-
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- if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_OVERRIDE))
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+ if (inode->i_op->permission) {
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+ ret = inode->i_op->permission(inode, MAY_EXEC);
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+ if (!ret)
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+ goto ok;
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+ return ret;
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+ }
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+ ret = acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl);
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+ if (!ret)
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goto ok;
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- if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH))
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+ if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
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goto ok;
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- return -EACCES;
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+ return ret;
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ok:
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return security_inode_permission(inode, MAY_EXEC);
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}
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@@ -853,12 +859,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd)
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nd->flags |= LOOKUP_CONTINUE;
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err = exec_permission_lite(inode);
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- if (err == -EAGAIN)
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- err = inode_permission(nd->path.dentry->d_inode,
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- MAY_EXEC);
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- if (!err)
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- err = ima_path_check(&nd->path, MAY_EXEC,
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- IMA_COUNT_UPDATE);
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if (err)
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break;
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