On Sun, Aug 22, 2021 at 4:49 AM <sumiyaw...@gmail.com> wrote: > > From: sumiyawang <sumiyaw...@tencent.com> > > kernel will crash when use after free the ioremap space, > which is triggered by ndctl destroy-namespace while some IO operations > exist. > The sequence of pmem driver release chain should be changed: > freeze the queue and wait io finished first, then iounmap. > > [47202.018374] BUG: unable to handle page fault for address: ffffc90080200000 > [47202.018822] CPU: 36 PID: 9606 Comm: systemd-udevd > [47202.020921] Call Trace: > [47202.020969] ? pmem_do_bvec+0xf9/0x3a0 > [47202.021036] ? xas_alloc+0x55/0xd0 > [47202.021094] pmem_rw_page+0x4b/0x80 > [47202.021159] bdev_read_page+0x86/0xb0 > [47202.021222] do_mpage_readpage+0x5d4/0x7a0 > [47202.021297] ? lru_cache_add+0xe/0x10 > [47202.021359] mpage_readpages+0xf9/0x1c0 > [47202.021428] ? bd_link_disk_holder+0x1a0/0x1a0 > [47202.021506] blkdev_readpages+0x1d/0x20 > [47202.021574] read_pages+0x67/0x1a0 > > ndctl Call Trace in vmcore: > PID: 23473 TASK: ffff88c4fbbe8000 CPU: 1 COMMAND: "ndctl" > __schedule > schedule > blk_mq_freeze_queue_wait > blk_freeze_queue > blk_cleanup_queue > pmem_release_queue > devm_action_release > release_nodes > devres_release_all > device_release_driver_internal > device_driver_detach > unbind_store > > At that time, the ioremap space is released
Thanks, looks good. I reworded the changelog a bit and added a "Cc: stable" as well as a "Fixes: 50f44ee7248a ("mm/devm_memremap_pages: fix final page put race")" tag. I'll send this up during the v5.15 merge window. https://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git/commit/?h=libnvdimm-fixes&id=32b2397c