=====================================================
BUG: KMSAN: uninit-value in process_srcu+0x168c/0x1b30 kernel/rcu/srcutree.c:1736
 process_srcu+0x168c/0x1b30 kernel/rcu/srcutree.c:1736
 process_one_work+0xb0d/0x1410 kernel/workqueue.c:2390
 worker_thread+0x107e/0x1d60 kernel/workqueue.c:2537
 kthread+0x31f/0x430 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Uninit was created at:
 slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774
 slab_alloc_node mm/slub.c:3452 [inline]
 __kmem_cache_alloc_node+0x518/0x920 mm/slub.c:3491
 kmalloc_trace+0x51/0x200 mm/slab_common.c:1061
 kmalloc include/linux/slab.h:580 [inline]
 blk_mq_alloc_tag_set+0xc86/0x1070 block/blk-mq.c:4460
 nbd_dev_add+0x2a8/0x11c0 drivers/block/nbd.c:1762
 nbd_init+0x483/0x590 drivers/block/nbd.c:2527
 do_one_initcall+0x229/0x8d0 init/main.c:1310
 do_initcall_level+0x140/0x350 init/main.c:1383
 do_initcalls+0xf0/0x1d0 init/main.c:1399
 do_basic_setup+0x22/0x30 init/main.c:1418
 kernel_init_freeable+0x308/0x4d0 init/main.c:1638
 kernel_init+0x2f/0x7e0 init/main.c:1526
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.3.0-rc5-syzkaller-g9189d4cb6980 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Workqueue: rcu_gp process_srcu
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