From: Dmitri Monakhov <dmonakhov@openvz.org>
Date: Mon, 1 Dec 2008 22:34:56 +0000 (-0800)
Subject: kill suid bit only for regular files
X-Git-Tag: v2.6.29-rc1~506^2~11
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=7f5ff766a7babd72fc192125e12ef5570effff4c

kill suid bit only for regular files

We don't have to do it because it is useless for non regular files.
In fact block device may trigger this path without dentry->d_inode->i_mutex.

(akpm: concerns were expressed (by me) about S_ISDIR inodes)

Signed-off-by: Dmitri Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/mm/filemap.c b/mm/filemap.c
index f3e5f89..ed53ce8 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1766,7 +1766,7 @@ int should_remove_suid(struct dentry *dentry)
 	if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
 		kill |= ATTR_KILL_SGID;
 
-	if (unlikely(kill && !capable(CAP_FSETID)))
+	if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
 		return kill;
 
 	return 0;