On Mon, 3 Apr 2017 14:17:29 +0900 Minchan Kim <minc...@kernel.org> wrote:
> Johannes Thumshirn reported system goes the panic when using NVMe over > Fabrics loopback target with zram. > > The reason is zram expects each bvec in bio contains a single page > but nvme can attach a huge bulk of pages attached to the bio's bvec > so that zram's index arithmetic could be wrong so that out-of-bound > access makes panic. > > It can be solved by limiting max_sectors with SECTORS_PER_PAGE like > [1] but it makes zram slow because bio should split with each pages > so this patch makes zram aware of multiple pages in a bvec so it > could solve without any regression. > > [1] 0bc315381fe9, zram: set physical queue limits to avoid array out of > bounds accesses This isn't a cleanup - it fixes a panic (or is it a BUG or is it an oops, or...) How serious is this bug? Should the fix be backported into -stable kernels? etc. A better description of the bug's behaviour would be appropriate. > Cc: Jens Axboe <ax...@kernel.dk> > Cc: Hannes Reinecke <h...@suse.com> > Reported-by: Johannes Thumshirn <jthumsh...@suse.de> > Tested-by: Johannes Thumshirn <jthumsh...@suse.de> > Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de> > Signed-off-by: Johannes Thumshirn <jthumsh...@suse.de> > Signed-off-by: Minchan Kim <minc...@kernel.org> This signoff trail is confusing. It somewhat implies that Johannes authored the patch which I don't think is the case?
