Commit e29841a0 authored Jul 13, 2016 by Vivek Goyal Committed by Miklos Szeredi Jul 29, 2016

ovl: dilute permission checks on lower only if not special file



Right now if file is on lower/, we remove MAY_WRITE/MAY_APPEND bits from
mask as lower/ will never be written and file will be copied up. But this
is not true for special files. These files are not copied up and are opened
in place. So don't dilute the checks for these types of files.

Reported-by: Dan Walsh <dwalsh@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

parent d837a49b

fs/overlayfs/inode.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -137,7 +137,7 @@ int ovl_permission(struct inode *inode, int mask)
		return err;

		old_cred = ovl_override_creds(inode->i_sb);
		if (!is_upper)
		if (!is_upper && !special_file(realinode->i_mode))
		mask &= ~(MAY_WRITE \| MAY_APPEND);
		err = inode_permission(realinode, mask);
		revert_creds(old_cred);

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