kernel/linux.git/drivers/nvdimm, branch v6.6.132

nvdimm/bus: Fix potential use after free in asynchronous initialization

2026-03-25T10:06:02+00:00

commit a8aec14230322ed8f1e8042b6d656c1631d41163 upstream. Dingisoul with KASAN reports a use after free if device_add() fails in nd_async_device_register(). Commit b6eae0f61db2 ("libnvdimm: Hold reference on parent while scheduling async init") correctly added a reference on the parent device to be held until asynchronous initialization was complete. However, if device_add() results in an allocation failure the ref count of the device drops to 0 prior to the parent pointer being accessed. Thus resulting in use after free. The bug bot AI correctly identified the fix. Save a reference to the parent pointer to be used to drop the parent reference regardless of the outcome of device_add(). Reported-by: Dingisoul Closes: http://lore.kernel.org/8855544b-be9e-4153-aa55-0bc328b13733@gmail.com Fixes: b6eae0f61db2 ("libnvdimm: Hold reference on parent while scheduling async init") Cc: stable@vger.kernel.org Reviewed-by: Dave Jiang Link: https://patch.msgid.link/20260306-fix-uaf-async-init-v1-1-a28fd7526723@intel.com Signed-off-by: Ira Weiny Signed-off-by: Greg Kroah-Hartman

nvdimm: virtio_pmem: serialize flush requests

2026-03-04T12:20:04+00:00

[ Upstream commit a9ba6733c7f1096c4506bf4e34a546e07242df74 ] Under heavy concurrent flush traffic, virtio-pmem can overflow its request virtqueue (req_vq): virtqueue_add_sgs() starts returning -ENOSPC and the driver logs "no free slots in the virtqueue". Shortly after that the device enters VIRTIO_CONFIG_S_NEEDS_RESET and flush requests fail with "virtio pmem device needs a reset". Serialize virtio_pmem_flush() with a per-device mutex so only one flush request is in-flight at a time. This prevents req_vq descriptor overflow under high concurrency. Reproducer (guest with virtio-pmem): - mkfs.ext4 -F /dev/pmem0 - mount -t ext4 -o dax,noatime /dev/pmem0 /mnt/bench - fio: ioengine=io_uring rw=randwrite bs=4k iodepth=64 numjobs=64 direct=1 fsync=1 runtime=30s time_based=1 - dmesg: "no free slots in the virtqueue" "virtio pmem device needs a reset" Fixes: 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver") Signed-off-by: Li Chen Acked-by: Pankaj Gupta Acked-by: Michael S. Tsirkin Link: https://patch.msgid.link/20260203021353.121091-1-me@linux.beauty Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin

libnvdimm/labels: Fix divide error in nd_label_data_init()

2025-06-04T12:41:56+00:00

[ Upstream commit ef1d3455bbc1922f94a91ed58d3d7db440652959 ] If a faulty CXL memory device returns a broken zero LSA size in its memory device information (Identify Memory Device (Opcode 4000h), CXL spec. 3.1, 8.2.9.9.1.1), a divide error occurs in the libnvdimm driver: Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:nd_label_data_init+0x10e/0x800 [libnvdimm] Code and flow: 1) CXL Command 4000h returns LSA size = 0 2) config_size is assigned to zero LSA size (CXL pmem driver): drivers/cxl/pmem.c: .config_size = mds->lsa_size, 3) max_xfer is set to zero (nvdimm driver): drivers/nvdimm/label.c: max_xfer = min_t(size_t, ndd->nsarea.max_xfer, config_size); 4) A subsequent DIV_ROUND_UP() causes a division by zero: drivers/nvdimm/label.c: /* Make our initial read size a multiple of max_xfer size */ drivers/nvdimm/label.c: read_size = min(DIV_ROUND_UP(read_size, max_xfer) * max_xfer, drivers/nvdimm/label.c- config_size); Fix this by checking the config size parameter by extending an existing check. Signed-off-by: Robert Richter Reviewed-by: Pankaj Gupta Reviewed-by: Ira Weiny Link: https://patch.msgid.link/20250320112223.608320-1-rrichter@amd.com Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin

nvdimm: rectify the illogical code within nd_dax_probe()

2024-12-14T19:00:13+00:00

[ Upstream commit b61352101470f8b68c98af674e187cfaa7c43504 ] When nd_dax is NULL, nd_pfn is consequently NULL as well. Nevertheless, it is inadvisable to perform pointer arithmetic or address-taking on a NULL pointer. Introduce the nd_dax_devinit() function to enhance the code's logic and improve its readability. Signed-off-by: Yi Yang Reviewed-by: Dave Jiang Link: https://patch.msgid.link/20241108085526.527957-1-yiyang13@huawei.com Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin

virtio_pmem: Check device status before requesting flush

2024-10-17T13:24:20+00:00

[ Upstream commit e25fbcd97cf52c3c9824d44b5c56c19673c3dd50 ] If a pmem device is in a bad status, the driver side could wait for host ack forever in virtio_pmem_flush(), causing the system to hang. So add a status check in the beginning of virtio_pmem_flush() to return early if the device is not activated. Signed-off-by: Philip Chen Message-Id: <20240826215313.2673566-1-philipchen@chromium.org> Signed-off-by: Michael S. Tsirkin Acked-by: Pankaj Gupta

nvdimm: Fix devs leaks in scan_labels()

2024-10-04T14:29:30+00:00

[ Upstream commit 62c2aa6b1f565d2fc1ec11a6e9e8336ce37a6426 ] scan_labels() leaks memory when label scanning fails and it falls back to just creating a default "seed" namespace for userspace to configure. Root can force the kernel to leak memory. Allocate the minimum resources unconditionally and release them when unneeded to avoid the memory leak. A kmemleak reports: unreferenced object 0xffff88800dda1980 (size 16): comm "kworker/u10:5", pid 69, jiffies 4294671781 hex dump (first 16 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 0): [<00000000c5dea560>] __kmalloc+0x32c/0x470 [<000000009ed43c83>] nd_region_register_namespaces+0x6fb/0x1120 [libnvdimm] [<000000000e07a65c>] nd_region_probe+0xfe/0x210 [libnvdimm] [<000000007b79ce5f>] nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm] [<00000000a5f3da2e>] really_probe+0xc6/0x390 [<00000000129e2a69>] __driver_probe_device+0x78/0x150 [<000000002dfed28b>] driver_probe_device+0x1e/0x90 [<00000000e7048de2>] __device_attach_driver+0x85/0x110 [<0000000032dca295>] bus_for_each_drv+0x85/0xe0 [<00000000391c5a7d>] __device_attach+0xbe/0x1e0 [<0000000026dabec0>] bus_probe_device+0x94/0xb0 [<00000000c590d936>] device_add+0x656/0x870 [<000000003d69bfaa>] nd_async_device_register+0xe/0x50 [libnvdimm] [<000000003f4c52a4>] async_run_entry_fn+0x2e/0x110 [<00000000e201f4b0>] process_one_work+0x1ee/0x600 [<000000006d90d5a9>] worker_thread+0x183/0x350 Cc: Dave Jiang Cc: Ira Weiny Fixes: 1b40e09a1232 ("libnvdimm: blk labels and namespace instantiation") Suggested-by: Dan Williams Signed-off-by: Li Zhijian Reviewed-by: Dan Williams Reviewed-by: Ira Weiny Link: https://patch.msgid.link/20240819062045.1481298-1-lizhijian@fujitsu.com Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin

nd_btt: Make BTT lanes preemptible

2023-11-20T10:59:19+00:00

[ Upstream commit 36c75ce3bd299878fd9b238e9803d3817ddafbf3 ] nd_region_acquire_lane uses get_cpu, which disables preemption. This is an issue on PREEMPT_RT kernels, since btt_write_pg and also nd_region_acquire_lane itself take a spin lock, resulting in BUG: sleeping function called from invalid context. Fix the issue by replacing get_cpu with smp_process_id and migrate_disable when needed. This makes BTT operations preemptible, thus permitting the use of spin_lock. BUG example occurring when running ndctl tests on PREEMPT_RT kernel: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 4903, name: libndctl preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 Preemption disabled at: [] nd_region_acquire_lane+0x15/0x90 [libnvdimm] Call Trace: dump_stack_lvl+0x8e/0xb0 __might_resched+0x19b/0x250 rt_spin_lock+0x4c/0x100 ? btt_write_pg+0x2d7/0x500 [nd_btt] btt_write_pg+0x2d7/0x500 [nd_btt] ? local_clock_noinstr+0x9/0xc0 btt_submit_bio+0x16d/0x270 [nd_btt] __submit_bio+0x48/0x80 __submit_bio_noacct+0x7e/0x1e0 submit_bio_wait+0x58/0xb0 __blkdev_direct_IO_simple+0x107/0x240 ? inode_set_ctime_current+0x51/0x110 ? __pfx_submit_bio_wait_endio+0x10/0x10 blkdev_write_iter+0x1d8/0x290 vfs_write+0x237/0x330 ... Fixes: 5212e11fde4d ("nd_btt: atomic sector updates") Signed-off-by: Tomas Glozar Reviewed-by: Ira Weiny Reviewed-by: Vishal Verma Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin

libnvdimm/of_pmem: Use devm_kstrdup instead of kstrdup and check its return value

2023-11-20T10:59:19+00:00

[ Upstream commit 6fd4ebfc4d61e3097b595ab2725d513e3bbd6739 ] Use devm_kstrdup() instead of kstrdup() and check its return value to avoid memory leak. Fixes: 49bddc73d15c ("libnvdimm/of_pmem: Provide a unique name for bus provider") Signed-off-by: Chen Ni Reviewed-by: Ira Weiny Reviewed-by: Dave Jiang Signed-off-by: Ira Weiny Signed-off-by: Sasha Levin

Merge tag 'libnvdimm-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2023-08-31T03:52:08+00:00

Pull nvdimm updates from Dave Jiang: "This is mostly small cleanups, fixes, and with a change to prevent zero-sized namespace exposed to user for nvdimm. Summary: - kstrtobool() conversion for nvdimm - Add REQ_OP_WRITE for virtio_pmem - Header files update for of_pmem - Restrict zero-sized namespace from being exposed to user - Avoid unnecessary endian conversion - Fix mem leak in nvdimm pmu - Fix dereference after free in nvdimm pmu" * tag 'libnvdimm-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: nvdimm: Fix dereference after free in register_nvdimm_pmu() nvdimm: Fix memleak of pmu attr_groups in unregister_nvdimm_pmu() nvdimm/pfn_dev: Avoid unnecessary endian conversion nvdimm/pfn_dev: Prevent the creation of zero-sized namespaces nvdimm: Explicitly include correct DT includes virtio_pmem: add the missing REQ_OP_WRITE for flush bio nvdimm: Use kstrtobool() instead of strtobool()

mm/hugepage pud: allow arch-specific helper function to check huge page pud support

2023-08-18T17:12:53+00:00

Patch series "Add support for DAX vmemmap optimization for ppc64", v6. This patch series implements changes required to support DAX vmemmap optimization for ppc64. The vmemmap optimization is only enabled with radix MMU translation and 1GB PUD mapping with 64K page size. The patch series also splits the hugetlb vmemmap optimization as a separate Kconfig variable so that architectures can enable DAX vmemmap optimization without enabling hugetlb vmemmap optimization. This should enable architectures like arm64 to enable DAX vmemmap optimization while they can't enable hugetlb vmemmap optimization. More details of the same are in patch "mm/vmemmap optimization: Split hugetlb and devdax vmemmap optimization". With 64K page size for 16384 pages added (1G) we save 14 pages With 4K page size for 262144 pages added (1G) we save 4094 pages With 4K page size for 512 pages added (2M) we save 6 pages This patch (of 13): Architectures like powerpc would like to enable transparent huge page pud support only with radix translation. To support that add has_transparent_pud_hugepage() helper that architectures can override. [aneesh.kumar@linux.ibm.com: use the new has_transparent_pud_hugepage()] Link: https://lkml.kernel.org/r/87tttrvtaj.fsf@linux.ibm.com Link: https://lkml.kernel.org/r/20230724190759.483013-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20230724190759.483013-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V Reviewed-by: Christophe Leroy Cc: Catalin Marinas Cc: Dan Williams Cc: Joao Martins Cc: Michael Ellerman Cc: Mike Kravetz Cc: Muchun Song Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Will Deacon Signed-off-by: Andrew Morton