# Redacted kdump excerpt — (Dell PowerEdge R750xa) # Contents: kernel banner, 'Modules linked in', and the two panic traces only. # Internal/personal identifiers anonymized: / ; timestamps, PIDs and CPU ids neutralized. [ 0.000000] Linux version 5.14.0-687.15.1.el9_8.x86_64 (mockbuild@x64-builder01.almalinux.org) (gcc (GCC) 11.5.0 20240719 (Red Hat 11.5.0-14), GNU ld version 2.35.2-72.el9) #1 SMP PREEMPT_DYNAMIC Thu Jun 11 08:51:45 EDT 2026 [ ] CIFS: VFS: \\ Error -32 sending data on socket to server [ ] ------------[ cut here ]------------ [ ] refcount_t: underflow; use-after-free. [ ] WARNING: CPU: PID: at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110 [ ] Modules linked in: binfmt_misc nls_utf8 cifs cifs_arc4 rdma_cm iw_cm ib_cm ib_core cifs_md4 dns_resolver nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink qrtr vfat fat nvidia_uvm(POE) nvidia_drm(POE) nvidia_modeset(POE) nvidia(POE) intel_rapl_msr intel_rapl_common intel_uncore_frequency intel_uncore_frequency_common i10nm_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm dell_wmi rapl ledtrig_audio intel_cstate sparse_keymap rfkill iTCO_wdt iTCO_vendor_support dcdbas ipmi_ssif dell_smbios wmi_bmof dell_wmi_descriptor drm_ttm_helper isst_if_mmio isst_if_mbox_pci intel_uncore ttm mei_me pcspkr video isst_if_common intel_th_gth mei i2c_i801 acpi_power_meter intel_th_pci intel_pch_thermal i2c_smbus ipmi_si intel_vsec intel_th acpi_ipmi ipmi_devintf ipmi_msghandler auth_rpcgss sunrpc xfs libcrc32c sd_mod sg mgag200 drm_client_lib [ ] i2c_algo_bit drm_shmem_helper drm_kms_helper ahci crct10dif_pclmul libahci crc32_pclmul crc32c_intel drm i40e libata megaraid_sas ghash_clmulni_intel tg3 libie libie_adminq wmi dm_mirror dm_region_hash dm_log dm_mod i2c_dev fuse [ ] CPU: PID: Comm: pt_main_thread Kdump: loaded Tainted: P OE ------ --- 5.14.0-687.15.1.el9_8.x86_64 #1 [ ] Hardware name: Dell Inc. PowerEdge R750xa, BIOS 1.20.2 01/16/2026 [ ] RIP: 0010:refcount_warn_saturate+0xba/0x110 [ ] Code: 01 01 e8 69 b1 a5 ff 0f 0b c3 cc cc cc cc 80 3d 74 61 c9 01 00 75 85 48 c7 c7 a8 4c 31 9e c6 05 64 61 c9 01 01 e8 46 b1 a5 ff <0f> 0b e9 0f b0 6a 00 80 3d 4f 61 c9 01 00 0f 85 5e ff ff ff 48 c7 [ ] RSP: 0018:ff77d49b26d3fb18 EFLAGS: 00010282 [ ] RAX: 0000000000000000 RBX: ff1f8fe70675eb40 RCX: 0000000000000027 [ ] RDX: 0000000000000027 RSI: 00000000ffff7fff RDI: ff1f900fafaa0f08 [ ] RBP: ff1f8fe078f841c0 R08: 0000000000000000 R09: ff77d49b26d3f9c0 [ ] R10: ff77d49b26d3f9b8 R11: ffffffff9ede2ee8 R12: ff1f8fe078f84000 [ ] R13: ff1f8fe193a26cc0 R14: 00000000ffffff99 R15: ff1f8fe078f841f8 [ ] FS: 00007f3e5bb01640(0000) GS:ff1f900fafa80000(0000) knlGS:0000000000000000 [ ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ ] CR2: 00002ac406c22400 CR3: 0000003089dac006 CR4: 0000000000773ef0 [ ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ ] PKRU: 55555554 [ ] Call Trace: [ ] [ ] ? __warn+0x84/0x140 [ ] ? refcount_warn_saturate+0xba/0x110 [ ] ? report_bug+0x16b/0x180 [ ] ? handle_bug+0x3c/0x70 [ ] ? exc_invalid_op+0x14/0x70 [ ] ? asm_exc_invalid_op+0x16/0x20 [ ] ? refcount_warn_saturate+0xba/0x110 [ ] ? refcount_warn_saturate+0xba/0x110 [ ] cifs_call_async+0x1ee/0x330 [cifs] [ ] smb2_async_writev+0x473/0x6f0 [cifs] [ ] ? __pfx_cifs_writedata_release+0x10/0x10 [cifs] [ ] ? cifs_writepages+0x52f/0xbc0 [cifs] [ ] cifs_writepages+0x52f/0xbc0 [cifs] [ ] ? generic_perform_write+0x14c/0x210 [ ] do_writepages+0xd5/0x1b0 [ ] ? cifs_strict_writev+0x1c4/0x330 [cifs] [ ] filemap_fdatawrite_wbc+0x66/0x90 [ ] __filemap_fdatawrite_range+0x54/0x80 [ ] filemap_write_and_wait_range+0x3e/0xb0 [ ] cifs_flush+0x73/0x120 [cifs] [ ] filp_flush+0x2e/0x80 [ ] __x64_sys_close+0x2e/0x80 [ ] do_syscall_64+0x5f/0xe0 [ ] ? do_user_addr_fault+0x35d/0x6a0 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ ] RIP: 0033:0x7f3e93903f3b [ ] Code: c3 66 0f 1f 44 00 00 48 8b 15 d9 6e 0f 00 f7 d8 64 89 02 b8 ff ff ff ff eb bc 0f 1f 44 00 00 f3 0f 1e fa b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 a9 6e 0f 00 f7 d8 [ ] RSP: 002b:00007f3e5baff178 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 [ ] RAX: ffffffffffffffda RBX: 00007f3d99ab1470 RCX: 00007f3e93903f3b [ ] RDX: 00007f3e939f79e0 RSI: 00000000fbad2404 RDI: 000000000000003e [ ] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ ] R10: 0000000000000200 R11: 0000000000000202 R12: 00007f3e939f85e0 [ ] R13: 00007f3e55ba4d20 R14: 00007f3e5baff300 R15: 00007f3d69e0a790 [ ] [ ] ---[ end trace 0000000000000000 ]--- [ ] ------------[ cut here ]------------ [ ] kernel BUG at mm/filemap.c:1593! [ ] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ ] CPU: PID: Comm: pt_main_thread Kdump: loaded Tainted: P W OE ------ --- 5.14.0-687.15.1.el9_8.x86_64 #1 [ ] Hardware name: Dell Inc. PowerEdge R750xa, BIOS 1.20.2 01/16/2026 [ ] RIP: 0010:folio_end_writeback+0x7d/0x80 [ ] Code: ff 4d 34 74 12 5d c3 cc cc cc cc f0 80 67 02 fb e8 e8 33 01 00 eb a9 48 89 ef 5d e9 5d 16 01 00 48 89 ee e8 c5 23 02 00 eb d5 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 [ ] RSP: 0018:ff77d49b26d3fc58 EFLAGS: 00010246 [ ] RAX: 0000000000000400 RBX: ff1f8fe082bafe00 RCX: 0000000000204008 [ ] RDX: 0000000000000001 RSI: 0000000000000206 RDI: ff1f8fe808712340 [ ] RBP: ffb7255315772740 R08: 0000000000000206 R09: ff77d49b26d3f9c0 [ ] R10: 0000000000000007 R11: ff1f8fe082bafe00 R12: 0000000000000470 [ ] R13: 0000000000000000 R14: ff77d49b26d3fde0 R15: ff1f8fb10802db00 [ ] FS: 00007f3e5bb01640(0000) GS:ff1f900fafa80000(0000) knlGS:0000000000000000 [ ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ ] CR2: 00002ac406c22400 CR3: 0000003089dac006 CR4: 0000000000773ef0 [ ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ ] PKRU: 55555554 [ ] Call Trace: [ ] [ ] ? die+0x33/0x90 [ ] ? do_trap+0xdf/0x110 [ ] ? folio_end_writeback+0x7d/0x80 [ ] ? do_error_trap+0x65/0x80 [ ] ? folio_end_writeback+0x7d/0x80 [ ] ? exc_invalid_op+0x4e/0x70 [ ] ? folio_end_writeback+0x7d/0x80 [ ] ? asm_exc_invalid_op+0x16/0x20 [ ] ? folio_end_writeback+0x7d/0x80 [ ] ? folio_end_writeback+0x1f/0x80 [ ] cifs_writepages+0x998/0xbc0 [cifs] [ ] do_writepages+0xd5/0x1b0 [ ] ? cifs_strict_writev+0x1c4/0x330 [cifs] [ ] filemap_fdatawrite_wbc+0x66/0x90 [ ] __filemap_fdatawrite_range+0x54/0x80 [ ] filemap_write_and_wait_range+0x3e/0xb0 [ ] cifs_flush+0x73/0x120 [cifs] [ ] filp_flush+0x2e/0x80 [ ] __x64_sys_close+0x2e/0x80 [ ] do_syscall_64+0x5f/0xe0 [ ] ? do_user_addr_fault+0x35d/0x6a0 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] ? clear_bhb_loop+0x40/0x90 [ ] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ ] RIP: 0033:0x7f3e93903f3b [ ] Code: c3 66 0f 1f 44 00 00 48 8b 15 d9 6e 0f 00 f7 d8 64 89 02 b8 ff ff ff ff eb bc 0f 1f 44 00 00 f3 0f 1e fa b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 a9 6e 0f 00 f7 d8 [ ] RSP: 002b:00007f3e5baff178 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 [ ] RAX: ffffffffffffffda RBX: 00007f3d99ab1470 RCX: 00007f3e93903f3b [ ] RDX: 00007f3e939f79e0 RSI: 00000000fbad2404 RDI: 000000000000003e [ ] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ ] R10: 0000000000000200 R11: 0000000000000202 R12: 00007f3e939f85e0 [ ] R13: 00007f3e55ba4d20 R14: 00007f3e5baff300 R15: 00007f3d69e0a790 [ ]