Commit 4cf27141 authored Jun 19, 2011 by Al Viro

make exec_permission(dir) really equivalent to inode_permission(dir, MAY_EXEC)

capability overrides apply only to the default case; if fs has ->permission()
that does _not_ call generic_permission(), we have no business doing them.
Moreover, if it has ->permission() that does call generic_permission(), we
have no need to recheck capabilities.

Besides, the capability overrides should apply only if we got EACCES from
acl_permission_check(); any other value (-EIO, etc.) should be returned
to caller, capabilities or not capabilities.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 43e15cdb

fs/namei.c

+9 −9

Original line number	Diff line number	Diff line
		@@ -584,19 +584,19 @@ static inline int exec_permission(struct inode *inode, unsigned int flags)

		if (inode->i_op->permission) {
		ret = inode->i_op->permission(inode, MAY_EXEC, flags);
		if (likely(!ret))
		goto ok;
		} else {
		ret = acl_permission_check(inode, MAY_EXEC, flags,
		inode->i_op->check_acl);
		}
		if (likely(!ret))
		goto ok;
		if (ret == -ECHILD)
		if (ret != -EACCES)
		return ret;

		if (ns_capable(ns, CAP_DAC_OVERRIDE) \|\|
		ns_capable(ns, CAP_DAC_READ_SEARCH))
		goto ok;

		}
		return ret;
		ok:
		return security_inode_exec_permission(inode, flags);