kernel/linux.git/drivers/nvdimm, branch v6.1.178

nvdimm/btt: Free arena sub-allocations on discover_arenas() error path

2026-07-24T13:55:01+00:00

commit 13fe4cd9ddd0aacb7777812328be525a11ea3fea upstream. Memory allocated by btt_freelist_init(), btt_rtt_init(), and btt_maplocks_init() is not freed on some discover_arenas() error paths. This leaks memory when arena discovery fails. Add the missing kfree() calls to release the allocations before returning an error. [ as: commit message and log edits ] Fixes: 5212e11fde4d ("nd_btt: atomic sector updates") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20260519-nvdimmleaks-v1-1-592300fb7a43@cse.iitm.ac.in Signed-off-by: Alison Schofield Signed-off-by: Greg Kroah-Hartman

nvdimm/btt: Free arenas on btt_init() error paths

2026-07-24T13:55:01+00:00

commit 1a6b6442a982d0ca5fb6a1a39b6f6dfd760eda57 upstream. The arenas allocated by discover_arenas() or create_arenas() are not freed on some error paths in btt_init(). This leaks memory when BTT initialization fails. Call free_arenas() from the affected error paths to release the allocations. [ as: commit message and log edits ] Fixes: 5212e11fde4d ("nd_btt: atomic sector updates") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20260519-nvdimmleaks-v1-2-592300fb7a43@cse.iitm.ac.in Signed-off-by: Alison Schofield Signed-off-by: Greg Kroah-Hartman

nvdimm/btt: Handle preemption in BTT lane acquisition

2026-07-24T13:54:38+00:00

[ Upstream commit 8d4b989d9c9afe5f185aa5853b666fc4617afe9e ] BTT lanes serialize access to per-lane metadata and workspace state during BTT I/O. The btt-check unit test reports data mismatches during BTT writes due to a race in lane acquisition that can lead to silent data corruption. The existing lane model uses a spinlock together with a per-CPU recursion count. That recursion model stopped being valid after BTT lanes became preemptible: another task can run on the same CPU, observe a non-zero recursion count, bypass locking, and use the same lane concurrently. BTT lanes are also held across arena_write_bytes() calls. That path reaches nsio_rw_bytes(), which flushes writes with nvdimm_flush(). Some provider flush callbacks can sleep, making a spinlock the wrong primitive for the lane lifetime. Replace the spinlock-based recursion model with a dynamically allocated per-lane mutex array and take the lane lock unconditionally. Add might_sleep() to catch any future atomic-context caller. Found with the ndctl unit test btt-check.sh. Fixes: 36c75ce3bd29 ("nd_btt: Make BTT lanes preemptible") Assisted-by: Claude-Sonnet:4.5 Tested-by: Aboorva Devarajan Reviewed-by: Aboorva Devarajan Reviewed-by: Vishal Verma Reviewed-by: Dave Jiang Link: https://patch.msgid.link/20260528021625.618462-1-alison.schofield@intel.com Signed-off-by: Alison Schofield Signed-off-by: Sasha Levin

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

2026-03-25T10:03:12+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

2026-03-04T12:19:53+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()

2025-06-04T12:40:04+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()

2024-12-14T18:54:47+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

2024-10-17T13:22:16+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()

2024-10-17T13:21:04+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

2023-11-20T10:52:05+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