The Device Model in ACRN through 2.5 has a devicemodel/core/mem.c use-after-free for a freed rb_entry.

The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size.

The dma_rx function in drivers/net/wireless/b43/dma.c in the Linux kernel before 2.6.39 does not properly allocate receive buffers, which allows remote attackers to cause a denial of service (system crash) via a crafted frame.

Linux kernel versions 4.9+ can be forced to make very expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for every incoming packet which can lead to a denial of service.

net/core/net_namespace.c in the Linux kernel 2.6.32 and earlier does not properly handle a high rate of creation and cleanup of network namespaces, which makes it easier for remote attackers to cause a denial of service (memory consumption) via requests to a daemon that requires a separate namespace per connection, as demonstrated by vsftpd.

The polling timer handler in ACRN before 2.5 has a use-after-free for a freed virtio device, related to devicemodel/hw/pci/virtio/*.c.

IBM Db2 for Linux, UNIX and Windows 12.1.0 and 12.1.1 is vulnerable to a denial of service as the server may crash under certain conditions with a specially crafted query.

The IPv6 implementation in the Linux kernel before 3.1 does not generate Fragment Identification values separately for each destination, which makes it easier for remote attackers to cause a denial of service (disrupted networking) by predicting these values and sending crafted packets.

Integer underflow in the dccp_parse_options function (net/dccp/options.c) in the Linux kernel before 2.6.33.14 allows remote attackers to cause a denial of service via a Datagram Congestion Control Protocol (DCCP) packet with an invalid feature options length, which triggers a buffer over-read.

iDrive RemotePC before 4.0.1 on Linux allows denial of service. A remote and unauthenticated attacker can disconnect a valid user session by connecting to an ephemeral port.

In the Linux kernel, the following vulnerability has been resolved: tcp: fix mptcp DSS corruption due to large pmtu xmit Syzkaller was able to trigger a DSS corruption: TCP: request_sock_subflow_v4: Possible SYN flooding on port [::]:20002. Sending cookies. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5227 at net/mptcp/protocol.c:695 __mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695 Modules linked in: CPU: 0 UID: 0 PID: 5227 Comm: syz-executor350 Not tainted 6.11.0-syzkaller-08829-gaf9c191ac2a0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__mptcp_move_skbs_from_subflow+0x20a9/0x21f0 net/mptcp/protocol.c:695 Code: 0f b6 dc 31 ff 89 de e8 b5 dd ea f5 89 d8 48 81 c4 50 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 98 da ea f5 90 <0f> 0b 90 e9 47 ff ff ff e8 8a da ea f5 90 0f 0b 90 e9 99 e0 ff ff RSP: 0018:ffffc90000006db8 EFLAGS: 00010246 RAX: ffffffff8ba9df18 RBX: 00000000000055f0 RCX: ffff888030023c00 RDX: 0000000000000100 RSI: 00000000000081e5 RDI: 00000000000055f0 RBP: 1ffff110062bf1ae R08: ffffffff8ba9cf12 R09: 1ffff110062bf1b8 R10: dffffc0000000000 R11: ffffed10062bf1b9 R12: 0000000000000000 R13: dffffc0000000000 R14: 00000000700cec61 R15: 00000000000081e5 FS: 000055556679c380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020287000 CR3: 0000000077892000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> move_skbs_to_msk net/mptcp/protocol.c:811 [inline] mptcp_data_ready+0x29c/0xa90 net/mptcp/protocol.c:854 subflow_data_ready+0x34a/0x920 net/mptcp/subflow.c:1490 tcp_data_queue+0x20fd/0x76c0 net/ipv4/tcp_input.c:5283 tcp_rcv_established+0xfba/0x2020 net/ipv4/tcp_input.c:6237 tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915 tcp_v4_rcv+0x2dc0/0x37f0 net/ipv4/tcp_ipv4.c:2350 ip_protocol_deliver_rcu+0x22e/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 </IRQ> <TASK> __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0x1764/0x3e80 net/core/dev.c:4451 dev_queue_xmit include/linux/netdevice.h:3094 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 ip_local_out net/ipv4/ip_output.c:130 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:536 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline] tcp_mtu_probe net/ipv4/tcp_output.c:2547 [inline] tcp_write_xmit+0x641d/0x6bf0 net/ipv4/tcp_output.c:2752 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3015 tcp_push_pending_frames include/net/tcp.h:2107 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5714 [inline] tcp_rcv_established+0x1026/0x2020 net/ipv4/tcp_input.c:6239 tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1915 sk_backlog_rcv include/net/sock.h:1113 [inline] __release_sock+0x214/0x350 net/core/sock.c:3072 release_sock+0x61/0x1f0 net/core/sock.c:3626 mptcp_push_ ---truncated---

The br_mdb_ip_get function in net/bridge/br_multicast.c in the Linux kernel before 2.6.35-rc5 allows remote attackers to cause a denial of service (NULL pointer dereference and system crash) via an IGMP packet, related to lack of a multicast table.

An issue was discovered in src/http/httpLib.c in EmbedThis Appweb Community Edition 8.2.1, allows attackers to cause a denial of service via the stream paramter to the parseUri function.

.NET, .NET Framework, and Visual Studio Denial of Service Vulnerability

The socket implementation in net/core/sock.c in the Linux kernel before 2.6.35 does not properly manage a backlog of received packets, which allows remote attackers to cause a denial of service by sending a large amount of network traffic, related to the sk_add_backlog function and the sk_rmem_alloc socket field. NOTE: this vulnerability exists because of an incomplete fix for CVE-2010-4251.

The socket implementation in net/core/sock.c in the Linux kernel before 2.6.34 does not properly manage a backlog of received packets, which allows remote attackers to cause a denial of service (memory consumption) by sending a large amount of network traffic, as demonstrated by netperf UDP tests.

.NET, .NET Framework, and Visual Studio Denial of Service Vulnerability

.NET and Visual Studio Denial of Service Vulnerability

A vulnerability exists in kernel/time/clocksource.c in the Linux kernel before 2.6.34 where on non-GENERIC_TIME systems (GENERIC_TIME=n), accessing /sys/devices/system/clocksource/clocksource0/current_clocksource results in an OOPS.

A certain Red Hat patch for net/ipv4/route.c in the Linux kernel 2.6.18 on Red Hat Enterprise Linux (RHEL) 5 allows remote attackers to cause a denial of service (deadlock) via crafted packets that force collisions in the IPv4 routing hash table, and trigger a routing "emergency" in which a hash chain is too long. NOTE: this is related to an issue in the Linux kernel before 2.6.31, when the kernel routing cache is disabled, involving an uninitialized pointer and a panic.

Certain WithSecure products have a buffer over-read whereby processing certain fuzz file types may cause a denial of service (DoS). This affects WithSecure Client Security 15, WithSecure Server Security 15, WithSecure Email and Server Security 15, WithSecure Elements Endpoint Protection 17 and later, WithSecure Client Security for Mac 15, WithSecure Elements Endpoint Protection for Mac 17 and later, WithSecure Linux Security 64 12.0, WithSecure Linux Protection 12.0, and WithSecure Atlant (formerly F-Secure Atlant) 15 and later.

IBM InfoSphere Information Server 11.7 could allow a remote attacker to cause a denial of service due to improper input validation. IBM X-Force ID: 265161.

IBM TXSeries for Multiplatforms 10.1 is vulnerable to a denial of service, caused by improper enforcement of the timeout on individual read operations. By conducting a slowloris-type attacks, a remote attacker could exploit this vulnerability to cause a denial of service.

IBM TXSeries for Multiplatforms 10.1 could allow a remote attacker to cause a denial of service using persistent connections due to improper allocation of resources.

A flaw was found in the Linux kernel's NFS implementation, all versions 3.x and all versions 4.x up to 4.20. An attacker, who is able to mount an exported NFS filesystem, is able to trigger a null pointer dereference by using an invalid NFS sequence. This can panic the machine and deny access to the NFS server. Any outstanding disk writes to the NFS server will be lost.

IBM Engineering Lifecycle Optimization - Publishing 7.0.2 and 7.0.3 could allow a remote attacker to cause a denial of service using a complex regular expression.

A vulnerability was found in drivers/cpufreq/qcom-cpufreq-hw.c in cpufreq subsystem in the Linux Kernel. This flaw, during device unbind will lead to double release problem leading to denial of service.

In the Linux kernel, the following vulnerability has been resolved: cppc_cpufreq: Fix possible null pointer dereference cppc_cpufreq_get_rate() and hisi_cppc_cpufreq_get_rate() can be called from different places with various parameters. So cpufreq_cpu_get() can return null as 'policy' in some circumstances. Fix this bug by adding null return check. Found by Linux Verification Center (linuxtesting.org) with SVACE.

Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) is vulnerable to a denial of service as the server terminates abnormally when executing a specially crafted SELECT statement. IBM X-Force ID: 200659.

The NFSv2/NFSv3 server in the nfsd subsystem in the Linux kernel through 4.10.11 allows remote attackers to cause a denial of service (system crash) via a long RPC reply, related to net/sunrpc/svc.c, fs/nfsd/nfs3xdr.c, and fs/nfsd/nfsxdr.c.

crypto/ahash.c in the Linux kernel through 4.10.9 allows attackers to cause a denial of service (API operation calling its own callback, and infinite recursion) by triggering EBUSY on a full queue.

A memory leak in the fsl_lpspi_probe() function in drivers/spi/spi-fsl-lpspi.c in the Linux kernel through 5.3.11 allows attackers to cause a denial of service (memory consumption) by triggering pm_runtime_get_sync() failures, aka CID-057b8945f78f. NOTE: third parties dispute the relevance of this because an attacker cannot realistically control these failures at probe time

A flaw was found in the networking subsystem of the Linux kernel within the handling of the RPL protocol. This issue results from the lack of proper handling of user-supplied data, which can lead to an assertion failure. This may allow an unauthenticated remote attacker to create a denial of service condition on the system.

IBM Secure External Authentication Server 2.4.3.2, 6.0.1, 6.0.2 and IBM Secure Proxy 3.4.3.2, 6.0.1, 6.0.2 could allow a remote user to consume resources causing a denial of service due to a resource leak.

Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 11.1.4 and 11.5.5 is vulnerable to a denial of service as the server terminates abnormally when executing a specially crafted SELECT statement. IBM X-Force ID: 200658.

A memory leak in the dwc3_pci_probe() function in drivers/usb/dwc3/dwc3-pci.c in the Linux kernel through 5.3.9 allows attackers to cause a denial of service (memory consumption) by triggering platform_device_add_properties() failures, aka CID-9bbfceea12a8.

A memory leak in the crypto_reportstat() function in drivers/virt/vboxguest/vboxguest_utils.c in the Linux kernel before 5.3.9 allows attackers to cause a denial of service (memory consumption) by triggering copy_form_user() failures, aka CID-e0b0cb938864.

.NET and Visual Studio Denial of Service Vulnerability

A memory leak in the fastrpc_dma_buf_attach() function in drivers/misc/fastrpc.c in the Linux kernel before 5.3.9 allows attackers to cause a denial of service (memory consumption) by triggering dma_get_sgtable() failures, aka CID-fc739a058d99.

An issue was discovered in the Linux kernel 4.4.x before 4.4.195. There is a NULL pointer dereference in rds_tcp_kill_sock() in net/rds/tcp.c that will cause denial of service, aka CID-91573ae4aed0.

A memory leak in the rsi_send_beacon() function in drivers/net/wireless/rsi/rsi_91x_mgmt.c in the Linux kernel through 5.3.11 allows attackers to cause a denial of service (memory consumption) by triggering rsi_prepare_beacon() failures, aka CID-d563131ef23c.

In the Linux kernel, the following vulnerability has been resolved: ice: fix uninitialized dplls mutex usage The pf->dplls.lock mutex is initialized too late, after its first use. Move it to the top of ice_dpll_init. Note that the "err_exit" error path destroys the mutex. And the mutex is the last thing destroyed in ice_dpll_deinit. This fixes the following warning with CONFIG_DEBUG_MUTEXES: ice 0000:10:00.0: The DDP package was successfully loaded: ICE OS Default Package version 1.3.36.0 ice 0000:10:00.0: 252.048 Gb/s available PCIe bandwidth (16.0 GT/s PCIe x16 link) ice 0000:10:00.0: PTP init successful ------------[ cut here ]------------ DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 0 PID: 410 at kernel/locking/mutex.c:587 __mutex_lock+0x773/0xd40 Modules linked in: crct10dif_pclmul crc32_pclmul crc32c_intel polyval_clmulni polyval_generic ice(+) nvme nvme_c> CPU: 0 PID: 410 Comm: kworker/0:4 Not tainted 6.8.0-rc5+ #3 Hardware name: HPE ProLiant DL110 Gen10 Plus/ProLiant DL110 Gen10 Plus, BIOS U56 10/19/2023 Workqueue: events work_for_cpu_fn RIP: 0010:__mutex_lock+0x773/0xd40 Code: c0 0f 84 1d f9 ff ff 44 8b 35 0d 9c 69 01 45 85 f6 0f 85 0d f9 ff ff 48 c7 c6 12 a2 a9 85 48 c7 c7 12 f1 a> RSP: 0018:ff7eb1a3417a7ae0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: 0000000000000002 RSI: ffffffff85ac2bff RDI: 00000000ffffffff RBP: ff7eb1a3417a7b80 R08: 0000000000000000 R09: 00000000ffffbfff R10: ff7eb1a3417a7978 R11: ff32b80f7fd2e568 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ff32b7f02c50e0d8 FS: 0000000000000000(0000) GS:ff32b80efe800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b5852cc000 CR3: 000000003c43a004 CR4: 0000000000771ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __warn+0x84/0x170 ? __mutex_lock+0x773/0xd40 ? report_bug+0x1c7/0x1d0 ? prb_read_valid+0x1b/0x30 ? handle_bug+0x42/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? __mutex_lock+0x773/0xd40 ? rcu_is_watching+0x11/0x50 ? __kmalloc_node_track_caller+0x346/0x490 ? ice_dpll_lock_status_get+0x28/0x50 [ice] ? __pfx_ice_dpll_lock_status_get+0x10/0x10 [ice] ? ice_dpll_lock_status_get+0x28/0x50 [ice] ice_dpll_lock_status_get+0x28/0x50 [ice] dpll_device_get_one+0x14f/0x2e0 dpll_device_event_send+0x7d/0x150 dpll_device_register+0x124/0x180 ice_dpll_init_dpll+0x7b/0xd0 [ice] ice_dpll_init+0x224/0xa40 [ice] ? _dev_info+0x70/0x90 ice_load+0x468/0x690 [ice] ice_probe+0x75b/0xa10 [ice] ? _raw_spin_unlock_irqrestore+0x4f/0x80 ? process_one_work+0x1a3/0x500 local_pci_probe+0x47/0xa0 work_for_cpu_fn+0x17/0x30 process_one_work+0x20d/0x500 worker_thread+0x1df/0x3e0 ? __pfx_worker_thread+0x10/0x10 kthread+0x103/0x140 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> irq event stamp: 125197 hardirqs last enabled at (125197): [<ffffffff8416409d>] finish_task_switch.isra.0+0x12d/0x3d0 hardirqs last disabled at (125196): [<ffffffff85134044>] __schedule+0xea4/0x19f0 softirqs last enabled at (105334): [<ffffffff84e1e65a>] napi_get_frags_check+0x1a/0x60 softirqs last disabled at (105332): [<ffffffff84e1e65a>] napi_get_frags_check+0x1a/0x60 ---[ end trace 0000000000000000 ]---

An issue was discovered in the Linux kernel before 5.0.7. A NULL pointer dereference can occur when megasas_create_frame_pool() fails in megasas_alloc_cmds() in drivers/scsi/megaraid/megaraid_sas_base.c. This causes a Denial of Service, related to a use-after-free.

In the Linux kernel, the following vulnerability has been resolved: s390/vfio-ap: always filter entire AP matrix The vfio_ap_mdev_filter_matrix function is called whenever a new adapter or domain is assigned to the mdev. The purpose of the function is to update the guest's AP configuration by filtering the matrix of adapters and domains assigned to the mdev. When an adapter or domain is assigned, only the APQNs associated with the APID of the new adapter or APQI of the new domain are inspected. If an APQN does not reference a queue device bound to the vfio_ap device driver, then it's APID will be filtered from the mdev's matrix when updating the guest's AP configuration. Inspecting only the APID of the new adapter or APQI of the new domain will result in passing AP queues through to a guest that are not bound to the vfio_ap device driver under certain circumstances. Consider the following: guest's AP configuration (all also assigned to the mdev's matrix): 14.0004 14.0005 14.0006 16.0004 16.0005 16.0006 unassign domain 4 unbind queue 16.0005 assign domain 4 When domain 4 is re-assigned, since only domain 4 will be inspected, the APQNs that will be examined will be: 14.0004 16.0004 Since both of those APQNs reference queue devices that are bound to the vfio_ap device driver, nothing will get filtered from the mdev's matrix when updating the guest's AP configuration. Consequently, queue 16.0005 will get passed through despite not being bound to the driver. This violates the linux device model requirement that a guest shall only be given access to devices bound to the device driver facilitating their pass-through. To resolve this problem, every adapter and domain assigned to the mdev will be inspected when filtering the mdev's matrix.

IBM MQ 9.2 LTS, 9.3 LTS, and 9.3 CD Internet Pass-Thru could allow a remote user to cause a denial of service by sending HTTP requests that would consume all available resources. IBM X-Force ID: 281278.

A bug affects the Linux kernel’s ksmbd NTLMv2 authentication and is known to crash the OS immediately in Linux-based systems.

A certain Red Hat patch to the sctp_sock_migrate function in net/sctp/socket.c in the Linux kernel before 2.6.21, as used in Red Hat Enterprise Linux (RHEL) 5, allows remote attackers to cause a denial of service (NULL pointer dereference and OOPS) via a crafted SCTP packet.

In the Linux kernel, the following vulnerability has been resolved: net: bridge: vlan: fix memory leak in __allowed_ingress When using per-vlan state, if vlan snooping and stats are disabled, untagged or priority-tagged ingress frame will go to check pvid state. If the port state is forwarding and the pvid state is not learning/forwarding, untagged or priority-tagged frame will be dropped but skb memory is not freed. Should free skb when __allowed_ingress returns false.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs It is observed sometimes when tethering is used over NCM with Windows 11 as host, at some instances, the gadget_giveback has one byte appended at the end of a proper NTB. When the NTB is parsed, unwrap call looks for any leftover bytes in SKB provided by u_ether and if there are any pending bytes, it treats them as a separate NTB and parses it. But in case the second NTB (as per unwrap call) is faulty/corrupt, all the datagrams that were parsed properly in the first NTB and saved in rx_list are dropped. Adding a few custom traces showed the following: [002] d..1 7828.532866: dwc3_gadget_giveback: ep1out: req 000000003868811a length 1025/16384 zsI ==> 0 [002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb toprocess: 1025 [002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb seq: 0xce67 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x400 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb ndp_len: 0x10 [002] d..1 7828.532869: ncm_unwrap_ntb: K: Parsed NTB with 1 frames In this case, the giveback is of 1025 bytes and block length is 1024. The rest 1 byte (which is 0x00) won't be parsed resulting in drop of all datagrams in rx_list. Same is case with packets of size 2048: [002] d..1 7828.557948: dwc3_gadget_giveback: ep1out: req 0000000011dfd96e length 2049/16384 zsI ==> 0 [002] d..1 7828.557949: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342 [002] d..1 7828.557950: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x800 Lecroy shows one byte coming in extra confirming that the byte is coming in from PC: Transfer 2959 - Bytes Transferred(1025) Timestamp((18.524 843 590) - Transaction 8391 - Data(1025 bytes) Timestamp(18.524 843 590) --- Packet 4063861 Data(1024 bytes) Duration(2.117us) Idle(14.700ns) Timestamp(18.524 843 590) --- Packet 4063863 Data(1 byte) Duration(66.160ns) Time(282.000ns) Timestamp(18.524 845 722) According to Windows driver, no ZLP is needed if wBlockLength is non-zero, because the non-zero wBlockLength has already told the function side the size of transfer to be expected. However, there are in-market NCM devices that rely on ZLP as long as the wBlockLength is multiple of wMaxPacketSize. To deal with such devices, it pads an extra 0 at end so the transfer is no longer multiple of wMaxPacketSize.