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>
This commit is contained in:
Vivek Goyal 2016-07-13 11:00:14 -04:00 committed by Miklos Szeredi
parent d837a49bd5
commit e29841a0ab

View File

@ -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);