Seen in the dmesg: [ 0.000000] ================================================================================ [ 0.000000] UBSAN: Undefined behaviour in lib/radix-tree.c:123:14 [ 0.000000] member access within null pointer of type 'const struct radix_tree_node' [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G T 4.16.0-rc4-next-20180307-dirty #559 [ 0.000000] Hardware name: Dell Inc. Latitude E6530/07Y85M, BIOS A20 05/08/2017 [ 0.000000] Call Trace: [ 0.000000] dump_stack+0x83/0xca [ 0.000000] ubsan_epilogue+0xd/0x3a [ 0.000000] handle_null_ptr_deref+0x85/0x90 [ 0.000000] __ubsan_handle_type_mismatch_v1+0x5e/0x70 [ 0.000000] __radix_tree_replace+0x1e4/0x1f0 [ 0.000000] radix_tree_iter_replace+0x25/0x50 [ 0.000000] idr_alloc_u32+0x166/0x1f0 [ 0.000000] idr_alloc+0x7e/0xd0 [ 0.000000] worker_pool_assign_id+0x61/0xd0 [ 0.000000] ? mutex_lock_nested+0x1b/0x20 [ 0.000000] workqueue_init_early+0x58a/0xc3f [ 0.000000] start_kernel+0x4f7/0x809 [ 0.000000] x86_64_start_reservations+0x40/0x61 [ 0.000000] x86_64_start_kernel+0x7b/0x9e [ 0.000000] secondary_startup_64+0xa5/0xb0 [ 0.000000] ================================================================================
not sure why a null 'parent' value got passed to get_slot_offset() in the first place, but it sounds like something is missing an 'if (NULL)' test...
pgp_P3u0T20Z_.pgp
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