Commit a3638d4f authored Jul 01, 2016 by Vivek Goyal Committed by Sasha Levin Aug 07, 2016

ovl: Copy up underlying inode's ->i_mode to overlay inode



[ Upstream commit 07a2daab49c549a37b5b744cbebb6e3f445f12bc ]

Right now when a new overlay inode is created, we initialize overlay
inode's ->i_mode from underlying inode ->i_mode but we retain only
file type bits (S_IFMT) and discard permission bits.

This patch changes it and retains permission bits too. This should allow
overlay to do permission checks on overlay inode itself in task context.

[SzM] It also fixes clearing suid/sgid bits on write.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reported-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

parent d4e1ac55

fs/overlayfs/inode.c

+1 −2

Original line number	Original line	Diff line number	Diff line
	@@ -399,12 +399,11 @@ struct inode ovl_new_inode(struct super_block sb, umode_t mode,
	if (!inode)		if (!inode)
	return NULL;		return NULL;

	mode &= S_IFMT;

	inode->i_ino = get_next_ino();		inode->i_ino = get_next_ino();
	inode->i_mode = mode;		inode->i_mode = mode;
	inode->i_flags \|= S_NOATIME \| S_NOCMTIME;		inode->i_flags \|= S_NOATIME \| S_NOCMTIME;

			mode &= S_IFMT;
	switch (mode) {		switch (mode) {
	case S_IFDIR:		case S_IFDIR:
	inode->i_private = oe;		inode->i_private = oe;

fs/overlayfs/overlayfs.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -173,6 +173,7 @@ static inline void ovl_copyattr(struct inode from, struct inode to)
	{		{
	to->i_uid = from->i_uid;		to->i_uid = from->i_uid;
	to->i_gid = from->i_gid;		to->i_gid = from->i_gid;
			to->i_mode = from->i_mode;
	}		}

	/* dir.c */		/* dir.c */