On Mon, 21 May 2018 15:35:24 -0700 Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > The last step before devm_memremap_pages() returns success is to > allocate a release action to tear the entire setup down. However, the > result from devm_add_action() is not checked. > > Checking the error also means that we need to handle the fact that the > percpu_ref may not be killed by the time devm_memremap_pages_release() > runs. Add a new state flag for this case. > > Cc: <stable@xxxxxxxxxxxxxxx> > Fixes: e8d513483300 ("memremap: change devm_memremap_pages interface...") > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx> > Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Why the cc:stable? The changelog doesn't describe the end-user-visible impact of the bug (it always should, for this reason). AFAICT we only go wrong when a small GFP_KERNEL allocation fails (basically never happens), with undescribed results :(