IBM MQ and IBM MQ Appliance 7.1, 7.5, 8.0, 9.0 LTS, 9.1 LTS, and 9.1 CD could allow a local attacker to obtain sensitive information by inclusion of sensitive data within runmqras data.

In the Linux kernel, the following vulnerability has been resolved: dma-buf: heaps: Fix potential spectre v1 gadget It appears like nr could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. [sumits: added fixes and cc: stable tags]

An issue was discovered in drivers/firmware/efi/efi.c in the Linux kernel before 5.4. Incorrect access permissions for the efivar_ssdt ACPI variable could be used by attackers to bypass lockdown or secure boot restrictions, aka CID-1957a85b0032.

A flaw was found in the fix for CVE-2019-11135, in the Linux upstream kernel versions before 5.5 where, the way Intel CPUs handle speculative execution of instructions when a TSX Asynchronous Abort (TAA) error occurs. When a guest is running on a host CPU affected by the TAA flaw (TAA_NO=0), but is not affected by the MDS issue (MDS_NO=1), the guest was to clear the affected buffers by using a VERW instruction mechanism. But when the MDS_NO=1 bit was exported to the guests, the guests did not use the VERW mechanism to clear the affected buffers. This issue affects guests running on Cascade Lake CPUs and requires that host has 'TSX' enabled. Confidentiality of data is the highest threat associated with this vulnerability.

In the Linux kernel through 5.3.8, f->fmt.sdr.reserved is uninitialized in rcar_drif_g_fmt_sdr_cap in drivers/media/platform/rcar_drif.c, which could cause a memory disclosure problem.

In wlan, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS07796900; Issue ID: ALPS07796900.

Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.

Copy_from_user on 64-bit versions of the Linux kernel does not implement the __uaccess_begin_nospec allowing a user to bypass the "access_ok" check and pass a kernel pointer to copy_from_user(). This would allow an attacker to leak information. We recommend upgrading beyond commit 74e19ef0ff8061ef55957c3abd71614ef0f42f47

In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because a certain preempting store operation does not necessarily occur before a store operation that has an attacker-controlled value.

Packages downloaded by Checkmk's automatic agent updates on Linux and Solaris have incorrect permissions in Checkmk < 2.4.0p1, < 2.3.0p32, < 2.2.0p42 and <= 2.1.0p49 (EOL). This allows a local attacker to read sensitive data.

In the Linux kernel, the following vulnerability has been resolved: iavf: Fix error handling in iavf_init_module() The iavf_init_module() won't destroy workqueue when pci_register_driver() failed. Call destroy_workqueue() when pci_register_driver() failed to prevent the resource leak. Similar to the handling of u132_hcd_init in commit f276e002793c ("usb: u132-hcd: fix resource leak")

An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel before 5.12. A bound check failure allows an attacker with special user (CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability.

The adjust_branches function in kernel/bpf/verifier.c in the Linux kernel before 4.5 does not consider the delta in the backward-jump case, which allows local users to obtain sensitive information from kernel memory by creating a packet filter and then loading crafted BPF instructions.

In wlan, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS07441605; Issue ID: ALPS07441605.

An issue was discovered in the Linux kernel before 5.11.11. qrtr_recvmsg in net/qrtr/qrtr.c allows attackers to obtain sensitive information from kernel memory because of a partially uninitialized data structure, aka CID-50535249f624.

In the Linux kernel through 5.13.7, an unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack.

A flaw named "EntryBleed" was found in the Linux Kernel Page Table Isolation (KPTI). This issue could allow a local attacker to leak KASLR base via prefetch side-channels based on TLB timing for Intel systems.

net/core/ethtool.c in the Linux kernel before 2.6.36 does not initialize certain data structures, which allows local users to obtain potentially sensitive information from kernel heap memory by leveraging the CAP_NET_ADMIN capability for an ethtool ioctl call.

The Tivoli Storage Manager (TSM) password may be displayed in plain text via application trace output while application tracing is enabled.

drivers/usb/mon/mon_bin.c in usbmon in the Linux kernel before 5.19.15 and 6.x before 6.0.1 allows a user-space client to corrupt the monitor's internal memory.

When sending malicous data to kernel by ioctl cmd FBIOPUT_VSCREENINFO,kernel will write memory out of bounds.

drivers/scsi/stex.c in the Linux kernel through 5.19.9 allows local users to obtain sensitive information from kernel memory because stex_queuecommand_lck lacks a memset for the PASSTHRU_CMD case.

Insertion of Sensitive Information into Temporary File vulnerability in Hitachi Infrastructure Analytics Advisor on Linux (Analytics probe component), Hitachi Ops Center Analyzer on Linux (Hitachi Ops Center Analyzer probe component) allows local users to gain sensitive information. This issue affects Hitachi Infrastructure Analytics Advisor: from 2.0.0-00 through 4.4.0-00; Hitachi Ops Center Analyzer: from 10.0.0-00 before 10.9.0-00.

The ovl_setattr function in fs/overlayfs/inode.c in the Linux kernel through 4.3.3 attempts to merge distinct setattr operations, which allows local users to bypass intended access restrictions and modify the attributes of arbitrary overlay files via a crafted application.

A flaw was found in the Linux kernel in versions prior to 5.10. A violation of memory access was found while detecting a padding of int3 in the linking state. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

In the Linux kernel, the following vulnerability has been resolved: xfrm: fix one more kernel-infoleak in algo dumping During fuzz testing, the following issue was discovered: BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x598/0x2a30 _copy_to_iter+0x598/0x2a30 __skb_datagram_iter+0x168/0x1060 skb_copy_datagram_iter+0x5b/0x220 netlink_recvmsg+0x362/0x1700 sock_recvmsg+0x2dc/0x390 __sys_recvfrom+0x381/0x6d0 __x64_sys_recvfrom+0x130/0x200 x64_sys_call+0x32c8/0x3cc0 do_syscall_64+0xd8/0x1c0 entry_SYSCALL_64_after_hwframe+0x79/0x81 Uninit was stored to memory at: copy_to_user_state_extra+0xcc1/0x1e00 dump_one_state+0x28c/0x5f0 xfrm_state_walk+0x548/0x11e0 xfrm_dump_sa+0x1e0/0x840 netlink_dump+0x943/0x1c40 __netlink_dump_start+0x746/0xdb0 xfrm_user_rcv_msg+0x429/0xc00 netlink_rcv_skb+0x613/0x780 xfrm_netlink_rcv+0x77/0xc0 netlink_unicast+0xe90/0x1280 netlink_sendmsg+0x126d/0x1490 __sock_sendmsg+0x332/0x3d0 ____sys_sendmsg+0x863/0xc30 ___sys_sendmsg+0x285/0x3e0 __x64_sys_sendmsg+0x2d6/0x560 x64_sys_call+0x1316/0x3cc0 do_syscall_64+0xd8/0x1c0 entry_SYSCALL_64_after_hwframe+0x79/0x81 Uninit was created at: __kmalloc+0x571/0xd30 attach_auth+0x106/0x3e0 xfrm_add_sa+0x2aa0/0x4230 xfrm_user_rcv_msg+0x832/0xc00 netlink_rcv_skb+0x613/0x780 xfrm_netlink_rcv+0x77/0xc0 netlink_unicast+0xe90/0x1280 netlink_sendmsg+0x126d/0x1490 __sock_sendmsg+0x332/0x3d0 ____sys_sendmsg+0x863/0xc30 ___sys_sendmsg+0x285/0x3e0 __x64_sys_sendmsg+0x2d6/0x560 x64_sys_call+0x1316/0x3cc0 do_syscall_64+0xd8/0x1c0 entry_SYSCALL_64_after_hwframe+0x79/0x81 Bytes 328-379 of 732 are uninitialized Memory access of size 732 starts at ffff88800e18e000 Data copied to user address 00007ff30f48aff0 CPU: 2 PID: 18167 Comm: syz-executor.0 Not tainted 6.8.11 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Fixes copying of xfrm algorithms where some random data of the structure fields can end up in userspace. Padding in structures may be filled with random (possibly sensitve) data and should never be given directly to user-space. A similar issue was resolved in the commit 8222d5910dae ("xfrm: Zero padding when dumping algos and encap") Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

IBM Jazz for Service Management 1.1.3.10 and IBM Tivoli Netcool/OMNIbus_GUI displays user credentials in plain clear text which can be read by a local user. IBM X-Force ID: 207610.

In the Linux kernel, the following vulnerability has been resolved: swiotlb: fix info leak with DMA_FROM_DEVICE The problem I'm addressing was discovered by the LTP test covering cve-2018-1000204. A short description of what happens follows: 1) The test case issues a command code 00 (TEST UNIT READY) via the SG_IO interface with: dxfer_len == 524288, dxdfer_dir == SG_DXFER_FROM_DEV and a corresponding dxferp. The peculiar thing about this is that TUR is not reading from the device. 2) In sg_start_req() the invocation of blk_rq_map_user() effectively bounces the user-space buffer. As if the device was to transfer into it. Since commit a45b599ad808 ("scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()") we make sure this first bounce buffer is allocated with GFP_ZERO. 3) For the rest of the story we keep ignoring that we have a TUR, so the device won't touch the buffer we prepare as if the we had a DMA_FROM_DEVICE type of situation. My setup uses a virtio-scsi device and the buffer allocated by SG is mapped by the function virtqueue_add_split() which uses DMA_FROM_DEVICE for the "in" sgs (here scatter-gather and not scsi generics). This mapping involves bouncing via the swiotlb (we need swiotlb to do virtio in protected guest like s390 Secure Execution, or AMD SEV). 4) When the SCSI TUR is done, we first copy back the content of the second (that is swiotlb) bounce buffer (which most likely contains some previous IO data), to the first bounce buffer, which contains all zeros. Then we copy back the content of the first bounce buffer to the user-space buffer. 5) The test case detects that the buffer, which it zero-initialized, ain't all zeros and fails. One can argue that this is an swiotlb problem, because without swiotlb we leak all zeros, and the swiotlb should be transparent in a sense that it does not affect the outcome (if all other participants are well behaved). Copying the content of the original buffer into the swiotlb buffer is the only way I can think of to make swiotlb transparent in such scenarios. So let's do just that if in doubt, but allow the driver to tell us that the whole mapped buffer is going to be overwritten, in which case we can preserve the old behavior and avoid the performance impact of the extra bounce.

In drivers/pci/hotplug/rpadlpar_sysfs.c in the Linux kernel through 5.11.8, the RPA PCI Hotplug driver has a user-tolerable buffer overflow when writing a new device name to the driver from userspace, allowing userspace to write data to the kernel stack frame directly. This occurs because add_slot_store and remove_slot_store mishandle drc_name '\0' termination, aka CID-cc7a0bb058b8.

A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.

In certain highly specific configurations of the host system and MongoDB server binary installation on Linux Operating Systems, it may be possible for a unintended actor with host-level access to cause the MongoDB Server binary to load unintended actor-controlled shared libraries when the server binary is started, potentially resulting in the unintended actor gaining full control over the MongoDB server process. This issue affects MongoDB Server v5.0 versions prior to 5.0.14 and MongoDB Server v6.0 versions prior to 6.0.3. Required Configuration: Only environments with Linux as the underlying operating system is affected by this issue

fs/ext4/extents.c in the Linux kernel through 5.1.2 does not zero out the unused memory region in the extent tree block, which might allow local users to obtain sensitive information by reading uninitialized data in the filesystem.

The actions implementation in the network queueing functionality in the Linux kernel before 2.6.36-rc2 does not properly initialize certain structure members when performing dump operations, which allows local users to obtain potentially sensitive information from kernel memory via vectors related to (1) the tcf_gact_dump function in net/sched/act_gact.c, (2) the tcf_mirred_dump function in net/sched/act_mirred.c, (3) the tcf_nat_dump function in net/sched/act_nat.c, (4) the tcf_simp_dump function in net/sched/act_simple.c, and (5) the tcf_skbedit_dump function in net/sched/act_skbedit.c.

Dell Client Platform Firmware Update Utility contains an Improper Link Resolution vulnerability. A high privileged attacker with local access could potentially exploit this vulnerability, leading to Elevation of Privileges.

In the Linux kernel, the following vulnerability has been resolved: nouveau/dmem: Fix vulnerability in migrate_to_ram upon copy error The `nouveau_dmem_copy_one` function ensures that the copy push command is sent to the device firmware but does not track whether it was executed successfully. In the case of a copy error (e.g., firmware or hardware failure), the copy push command will be sent via the firmware channel, and `nouveau_dmem_copy_one` will likely report success, leading to the `migrate_to_ram` function returning a dirty HIGH_USER page to the user. This can result in a security vulnerability, as a HIGH_USER page that may contain sensitive or corrupted data could be returned to the user. To prevent this vulnerability, we allocate a zero page. Thus, in case of an error, a non-dirty (zero) page will be returned to the user.

In the Linux kernel, the following vulnerability has been resolved: bonding: Fix unnecessary warnings and logs from bond_xdp_get_xmit_slave() syzbot reported a WARNING in bond_xdp_get_xmit_slave. To reproduce this[1], one bond device (bond1) has xdpdrv, which increases bpf_master_redirect_enabled_key. Another bond device (bond0) which is unsupported by XDP but its slave (veth3) has xdpgeneric that returns XDP_TX. This triggers WARN_ON_ONCE() from the xdp_master_redirect(). To reduce unnecessary warnings and improve log management, we need to delete the WARN_ON_ONCE() and add ratelimit to the netdev_err(). [1] Steps to reproduce: # Needs tx_xdp with return XDP_TX; ip l add veth0 type veth peer veth1 ip l add veth3 type veth peer veth4 ip l add bond0 type bond mode 6 # BOND_MODE_ALB, unsupported by XDP ip l add bond1 type bond # BOND_MODE_ROUNDROBIN by default ip l set veth0 master bond1 ip l set bond1 up # Increases bpf_master_redirect_enabled_key ip l set dev bond1 xdpdrv object tx_xdp.o section xdp_tx ip l set veth3 master bond0 ip l set bond0 up ip l set veth4 up # Triggers WARN_ON_ONCE() from the xdp_master_redirect() ip l set veth3 xdpgeneric object tx_xdp.o section xdp_tx

In the Linux kernel, the following vulnerability has been resolved: icmp: change the order of rate limits ICMP messages are ratelimited : After the blamed commits, the two rate limiters are applied in this order: 1) host wide ratelimit (icmp_global_allow()) 2) Per destination ratelimit (inetpeer based) In order to avoid side-channels attacks, we need to apply the per destination check first. This patch makes the following change : 1) icmp_global_allow() checks if the host wide limit is reached. But credits are not yet consumed. This is deferred to 3) 2) The per destination limit is checked/updated. This might add a new node in inetpeer tree. 3) icmp_global_consume() consumes tokens if prior operations succeeded. This means that host wide ratelimit is still effective in keeping inetpeer tree small even under DDOS. As a bonus, I removed icmp_global.lock as the fast path can use a lock-free operation.

In the Linux kernel, the following vulnerability has been resolved: KEYS: trusted: dcp: fix leak of blob encryption key Trusted keys unseal the key blob on load, but keep the sealed payload in the blob field so that every subsequent read (export) will simply convert this field to hex and send it to userspace. With DCP-based trusted keys, we decrypt the blob encryption key (BEK) in the Kernel due hardware limitations and then decrypt the blob payload. BEK decryption is done in-place which means that the trusted key blob field is modified and it consequently holds the BEK in plain text. Every subsequent read of that key thus send the plain text BEK instead of the encrypted BEK to userspace. This issue only occurs when importing a trusted DCP-based key and then exporting it again. This should rarely happen as the common use cases are to either create a new trusted key and export it, or import a key blob and then just use it without exporting it again. Fix this by performing BEK decryption and encryption in a dedicated buffer. Further always wipe the plain text BEK buffer to prevent leaking the key via uninitialized memory.

IBM Security Verify Bridge Directory Sync 1.0.1 through 1.0.12, IBM Security Verify Gateway for Windows Login 1.0.1 through 1.0.10, and IBM Security Verify Gateway for Radius 1.0.1 through 1.0.11 stores user credentials in configuration files which can be read by a local user.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

The swiotlb_print_info function in lib/swiotlb.c in the Linux kernel through 4.14.14 allows local users to obtain sensitive address information by reading dmesg data from a "software IO TLB" printk call.

In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrum_acl_tcam: Fix stack corruption When tc filters are first added to a net device, the corresponding local port gets bound to an ACL group in the device. The group contains a list of ACLs. In turn, each ACL points to a different TCAM region where the filters are stored. During forwarding, the ACLs are sequentially evaluated until a match is found. One reason to place filters in different regions is when they are added with decreasing priorities and in an alternating order so that two consecutive filters can never fit in the same region because of their key usage. In Spectrum-2 and newer ASICs the firmware started to report that the maximum number of ACLs in a group is more than 16, but the layout of the register that configures ACL groups (PAGT) was not updated to account for that. It is therefore possible to hit stack corruption [1] in the rare case where more than 16 ACLs in a group are required. Fix by limiting the maximum ACL group size to the minimum between what the firmware reports and the maximum ACLs that fit in the PAGT register. Add a test case to make sure the machine does not crash when this condition is hit. [1] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: mlxsw_sp_acl_tcam_group_update+0x116/0x120 [...] dump_stack_lvl+0x36/0x50 panic+0x305/0x330 __stack_chk_fail+0x15/0x20 mlxsw_sp_acl_tcam_group_update+0x116/0x120 mlxsw_sp_acl_tcam_group_region_attach+0x69/0x110 mlxsw_sp_acl_tcam_vchunk_get+0x492/0xa20 mlxsw_sp_acl_tcam_ventry_add+0x25/0xe0 mlxsw_sp_acl_rule_add+0x47/0x240 mlxsw_sp_flower_replace+0x1a9/0x1d0 tc_setup_cb_add+0xdc/0x1c0 fl_hw_replace_filter+0x146/0x1f0 fl_change+0xc17/0x1360 tc_new_tfilter+0x472/0xb90 rtnetlink_rcv_msg+0x313/0x3b0 netlink_rcv_skb+0x58/0x100 netlink_unicast+0x244/0x390 netlink_sendmsg+0x1e4/0x440 ____sys_sendmsg+0x164/0x260 ___sys_sendmsg+0x9a/0xe0 __sys_sendmsg+0x7a/0xc0 do_syscall_64+0x40/0xe0 entry_SYSCALL_64_after_hwframe+0x63/0x6b

In the Linux kernel, the following vulnerability has been resolved: gpio: prevent potential speculation leaks in gpio_device_get_desc() Userspace may trigger a speculative read of an address outside the gpio descriptor array. Users can do that by calling gpio_ioctl() with an offset out of range. Offset is copied from user and then used as an array index to get the gpio descriptor without sanitization in gpio_device_get_desc(). This change ensures that the offset is sanitized by using array_index_nospec() to mitigate any possibility of speculative information leaks. This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc.

IBM EntireX 11.1 could allow a local user to obtain sensitive information when a detailed technical error message is returned. This information could be used in further attacks against the system.

Improper access control in some Intel(R) Aptio* V UEFI Firmware Integrator Tools before version iDmi Windows 5.27.03.0003 may allow a privileged user to potentially enable escalation of privilege via local access.

Improper access control in some Intel(R) Aptio* V UEFI Firmware Integrator Tools before version iDmiEdit-Linux-5.27.06.0017 may allow a privileged user to potentially enable escalation of privilege via local access.

In IOMMU, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: DTV03692061; Issue ID: DTV03692061.

In the Linux kernel, the following vulnerability has been resolved: x86: fix user address masking non-canonical speculation issue It turns out that AMD has a "Meltdown Lite(tm)" issue with non-canonical accesses in kernel space. And so using just the high bit to decide whether an access is in user space or kernel space ends up with the good old "leak speculative data" if you have the right gadget using the result: CVE-2020-12965 “Transient Execution of Non-Canonical Accesses“ Now, the kernel surrounds the access with a STAC/CLAC pair, and those instructions end up serializing execution on older Zen architectures, which closes the speculation window. But that was true only up until Zen 5, which renames the AC bit [1]. That improves performance of STAC/CLAC a lot, but also means that the speculation window is now open. Note that this affects not just the new address masking, but also the regular valid_user_address() check used by access_ok(), and the asm version of the sign bit check in the get_user() helpers. It does not affect put_user() or clear_user() variants, since there's no speculative result to be used in a gadget for those operations.

kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.

In the Linux kernel, the following vulnerability has been resolved: USB: usbtmc: prevent kernel-usb-infoleak The syzbot reported a kernel-usb-infoleak in usbtmc_write, we need to clear the structure before filling fields.