Hi, panic happened when we run jobs on 5.8.6-rc2-650d8f2: https://beaker.engineering.redhat.com/recipes/8756377#task115008997 and the core trace is as follows, have you ever seen this before? [ 7522.385926] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 7522.393694] #PF: supervisor read access in kernel mode [ 7522.399425] #PF: error_code(0x0000) - not-present page [ 7522.405154] PGD 0 P4D 0 [ 7522.407977] Oops: 0000 [#1] SMP PTI [ 7522.411866] CPU: 14 PID: 668 Comm: kworker/14:1H Kdump: loaded Tainted: G L 5.8.6-rc2-650d8f2.cki #1 [ 7522.423510] Hardware name: Dell Inc. PowerEdge R630/0CNCJW, BIOS 1.2.10 03/09/2015 [ 7522.431959] Workqueue: kblockd blk_mq_run_work_fn [ 7522.437206] RIP: 0010:__list_del_entry_valid+0x2d/0x4c [ 7522.442936] Code: 4c 8b 47 08 48 b8 00 01 00 00 00 00 ad de 48 39 c2 0f 84 71 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c0 0f 84 91 00 00 00 <49> 8b 30 48 39 fe 0f 85 71 00 00 00 48 8b 52 08 48 39 f2 0f 85 56 [ 7522.463891] RSP: 0018:ffffa5b9009dfcd8 EFLAGS: 00010017 [ 7522.469719] RAX: dead000000000122 RBX: ffff8b458d4c9950 RCX: 0000000000000000 [ 7522.477680] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8b448a753938 [ 7522.485640] RBP: ffff8b448a753898 R08: 0000000000000000 R09: ffff8b45bb6bb32c [ 7522.493600] R10: 0000000000000018 R11: 0000000000000018 R12: ffff8b448a753810 [ 7522.501560] R13: ffff8b44993e2800 R14: 0000000000000000 R15: ffff8b458d07c900 [ 7522.509520] FS: 0000000000000000(0000) GS:ffff8b45bfd80000(0000) knlGS:0000000000000000 [ 7522.518548] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 7522.524957] CR2: 0000000000000000 CR3: 0000000875570005 CR4: 00000000001606e0 [ 7522.532917] Call Trace: [ 7522.535647] bfq_idle_extract+0x52/0xb0 [ 7522.539926] bfq_put_idle_entity+0x12/0x60 [ 7522.544494] bfq_bfqq_served+0xb0/0x190 [ 7522.548770] bfq_dispatch_request+0x2c2/0x1070 [ 7522.553727] blk_mq_do_dispatch_sched+0xa4/0x140 [ 7522.558879] ? newidle_balance+0x1c0/0x390 [ 7522.563446] __blk_mq_sched_dispatch_requests+0x159/0x160 [ 7522.569467] blk_mq_sched_dispatch_requests+0x30/0x60 [ 7522.575102] __blk_mq_run_hw_queue+0x49/0x110 [ 7522.579962] process_one_work+0x1b4/0x370 [ 7522.584434] worker_thread+0x53/0x3e0 [ 7522.588517] ? process_one_work+0x370/0x370 [ 7522.593180] kthread+0x119/0x140 [ 7522.596779] ? __kthread_bind_mask+0x60/0x60 [ 7522.601541] ret_from_fork+0x22/0x30 [ 7522.605528] Modules linked in: scsi_transport_iscsi crypto_user can_bcm pptp gre l2tp_ip6 l2tp_ip l2tp_core ip6_udp_tunnel udp_tunnel rfcomm can_raw hidp bnep nfc af_key mpls_router ip_tunnel vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport vsock vmw_vmci kcm ieee802154_socket ieee802154 bluetooth ecdh_generic ecc fcrypt pcbc rxrpc pppoe pppox smc ib_core atm can mlx4_en mlx4_core n_gsm pps_ldisc slcan ppp_synctty n_hdlc mkiss ax25 ppp_async ppp_generic slip slhc nls_utf8 isofs minix binfmt_misc nfsv3 nfs_acl rds brd exfat vfat fat loop sctp tun xt_multiport xt_nat xt_addrtype xt_mark xt_conntrack xt_MASQUERADE nft_counter xt_comment nft_compat nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink overlay fuse rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache rfkill intel_rapl_msr intel_rapl_common sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp iTCO_wdt intel_pmc_bxt iTCO_vendor_support sunrpc dcdbas [ 7522.605556] kvm_intel kvm irqbypass rapl intel_cstate intel_uncore pcspkr ipmi_ssif lpc_ich mei_me mei igb dca ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter ip_tables xfs mgag200 lpfc drm_vram_helper drm_kms_helper cec nvmet_fc drm_ttm_helper nvmet ttm crct10dif_pclmul nvme_fc crc32_pclmul crc32c_intel nvme_fabrics drm ghash_clmulni_intel i2c_algo_bit nvme_core megaraid_sas scsi_transport_fc wmi [last unloaded: dummy] [ 7522.744918] CR2: 0000000000000000 [ 7522.748613] ---[ end trace ed34032a61d7e2a6 ]--- Thanks & Best Regards, Jianlin Shi
