On Tue, Jun 04, 2019 at 07:00:39PM +0100, Ben Hutchings wrote: > This reverts commit 84ecc2f6eb1cb12e6d44818f94fa49b50f06e6ac. > > con_insert_unipair() is working with a sparse 3-dimensional array: > > - p->uni_pgdir[] is the top layer > - p1 points to a middle layer > - p2 points to a bottom layer > > If it needs to allocate a new middle layer, and then fails to allocate > a new bottom layer, it would previously free only p2, and now it frees > both p1 and p2. But since the new middle layer was already registered > in the top layer, it was not leaked. > > However, if it looks up an *existing* middle layer and then fails to > allocate a bottom layer, it now frees both p1 and p2 but does *not* > free any other bottom layers under p1. So it *introduces* a memory > leak. > > The error path also cleared the wrong index in p->uni_pgdir[], > introducing a use-after-free. > > Signed-off-by: Ben Hutchings <[email protected]>
Now applied, thanks. Gen, please be careful with these types of "fixes"... thanks, greg k-h
