Search Results (339475 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2022-50725 1 Linux 1 Linux Kernel 2025-12-29 N/A
In the Linux kernel, the following vulnerability has been resolved: media: vidtv: Fix use-after-free in vidtv_bridge_dvb_init() KASAN reports a use-after-free: BUG: KASAN: use-after-free in dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core] Call Trace: ... dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core] vidtv_bridge_probe+0x7bf/0xa40 [dvb_vidtv_bridge] platform_probe+0xb6/0x170 ... Allocated by task 1238: ... dvb_register_device+0x1a7/0xa70 [dvb_core] dvb_dmxdev_init+0x2af/0x4a0 [dvb_core] vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge] ... Freed by task 1238: dvb_register_device+0x6d2/0xa70 [dvb_core] dvb_dmxdev_init+0x2af/0x4a0 [dvb_core] vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge] ... It is because the error handling in vidtv_bridge_dvb_init() is wrong. First, vidtv_bridge_dmx(dev)_init() will clean themselves when fail, but goto fail_dmx(_dev): calls release functions again, which causes use-after-free. Also, in fail_fe, fail_tuner_probe and fail_demod_probe, j = i will cause out-of-bound when i finished its loop (i == NUM_FE). And the loop releasing is wrong, although now NUM_FE is 1 so it won't cause problem. Fix this by correctly releasing everything.
CVE-2022-50773 1 Linux 1 Linux Kernel 2025-12-29 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: ALSA: mts64: fix possible null-ptr-defer in snd_mts64_interrupt I got a null-ptr-defer error report when I do the following tests on the qemu platform: make defconfig and CONFIG_PARPORT=m, CONFIG_PARPORT_PC=m, CONFIG_SND_MTS64=m Then making test scripts: cat>test_mod1.sh<<EOF modprobe snd-mts64 modprobe snd-mts64 EOF Executing the script, perhaps several times, we will get a null-ptr-defer report, as follow: syzkaller:~# ./test_mod.sh snd_mts64: probe of snd_mts64.0 failed with error -5 modprobe: ERROR: could not insert 'snd_mts64': No such device BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 0 PID: 205 Comm: modprobe Not tainted 6.1.0-rc8-00588-g76dcd734eca2 #6 Call Trace: <IRQ> snd_mts64_interrupt+0x24/0xa0 [snd_mts64] parport_irq_handler+0x37/0x50 [parport] __handle_irq_event_percpu+0x39/0x190 handle_irq_event_percpu+0xa/0x30 handle_irq_event+0x2f/0x50 handle_edge_irq+0x99/0x1b0 __common_interrupt+0x5d/0x100 common_interrupt+0xa0/0xc0 </IRQ> <TASK> asm_common_interrupt+0x22/0x40 RIP: 0010:_raw_write_unlock_irqrestore+0x11/0x30 parport_claim+0xbd/0x230 [parport] snd_mts64_probe+0x14a/0x465 [snd_mts64] platform_probe+0x3f/0xa0 really_probe+0x129/0x2c0 __driver_probe_device+0x6d/0xc0 driver_probe_device+0x1a/0xa0 __device_attach_driver+0x7a/0xb0 bus_for_each_drv+0x62/0xb0 __device_attach+0xe4/0x180 bus_probe_device+0x82/0xa0 device_add+0x550/0x920 platform_device_add+0x106/0x220 snd_mts64_attach+0x2e/0x80 [snd_mts64] port_check+0x14/0x20 [parport] bus_for_each_dev+0x6e/0xc0 __parport_register_driver+0x7c/0xb0 [parport] snd_mts64_module_init+0x31/0x1000 [snd_mts64] do_one_initcall+0x3c/0x1f0 do_init_module+0x46/0x1c6 load_module+0x1d8d/0x1e10 __do_sys_finit_module+0xa2/0xf0 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> Kernel panic - not syncing: Fatal exception in interrupt Rebooting in 1 seconds.. The mts wa not initialized during interrupt, we add check for mts to fix this bug.
CVE-2022-50774 1 Linux 1 Linux Kernel 2025-12-29 7.0 High
In the Linux kernel, the following vulnerability has been resolved: crypto: qat - fix DMA transfer direction When CONFIG_DMA_API_DEBUG is selected, while running the crypto self test on the QAT crypto algorithms, the function add_dma_entry() reports a warning similar to the one below, saying that overlapping mappings are not supported. This occurs in tests where the input and the output scatter list point to the same buffers (i.e. two different scatter lists which point to the same chunks of memory). The logic that implements the mapping uses the flag DMA_BIDIRECTIONAL for both the input and the output scatter lists which leads to overlapped write mappings. These are not supported by the DMA layer. Fix by specifying the correct DMA transfer directions when mapping buffers. For in-place operations where the input scatter list matches the output scatter list, buffers are mapped once with DMA_BIDIRECTIONAL, otherwise input buffers are mapped using the flag DMA_TO_DEVICE and output buffers are mapped with DMA_FROM_DEVICE. Overlapping a read mapping with a write mapping is a valid case in dma-coherent devices like QAT. The function that frees and unmaps the buffers, qat_alg_free_bufl() has been changed accordingly to the changes to the mapping function. DMA-API: 4xxx 0000:06:00.0: cacheline tracking EEXIST, overlapping mappings aren't supported WARNING: CPU: 53 PID: 4362 at kernel/dma/debug.c:570 add_dma_entry+0x1e9/0x270 ... Call Trace: dma_map_page_attrs+0x82/0x2d0 ? preempt_count_add+0x6a/0xa0 qat_alg_sgl_to_bufl+0x45b/0x990 [intel_qat] qat_alg_aead_dec+0x71/0x250 [intel_qat] crypto_aead_decrypt+0x3d/0x70 test_aead_vec_cfg+0x649/0x810 ? number+0x310/0x3a0 ? vsnprintf+0x2a3/0x550 ? scnprintf+0x42/0x70 ? valid_sg_divisions.constprop.0+0x86/0xa0 ? test_aead_vec+0xdf/0x120 test_aead_vec+0xdf/0x120 alg_test_aead+0x185/0x400 alg_test+0x3d8/0x500 ? crypto_acomp_scomp_free_ctx+0x30/0x30 ? __schedule+0x32a/0x12a0 ? ttwu_queue_wakelist+0xbf/0x110 ? _raw_spin_unlock_irqrestore+0x23/0x40 ? try_to_wake_up+0x83/0x570 ? _raw_spin_unlock_irqrestore+0x23/0x40 ? __set_cpus_allowed_ptr_locked+0xea/0x1b0 ? crypto_acomp_scomp_free_ctx+0x30/0x30 cryptomgr_test+0x27/0x50 kthread+0xe6/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30
CVE-2022-50772 1 Linux 1 Linux Kernel 2025-12-29 7.0 High
In the Linux kernel, the following vulnerability has been resolved: netdevsim: fix memory leak in nsim_bus_dev_new() If device_register() failed in nsim_bus_dev_new(), the value of reference in nsim_bus_dev->dev is 1. obj->name in nsim_bus_dev->dev will not be released. unreferenced object 0xffff88810352c480 (size 16): comm "echo", pid 5691, jiffies 4294945921 (age 133.270s) hex dump (first 16 bytes): 6e 65 74 64 65 76 73 69 6d 31 00 00 00 00 00 00 netdevsim1...... backtrace: [<000000005e2e5e26>] __kmalloc_node_track_caller+0x3a/0xb0 [<0000000094ca4fc8>] kvasprintf+0xc3/0x160 [<00000000aad09bcc>] kvasprintf_const+0x55/0x180 [<000000009bac868d>] kobject_set_name_vargs+0x56/0x150 [<000000007c1a5d70>] dev_set_name+0xbb/0xf0 [<00000000ad0d126b>] device_add+0x1f8/0x1cb0 [<00000000c222ae24>] new_device_store+0x3b6/0x5e0 [<0000000043593421>] bus_attr_store+0x72/0xa0 [<00000000cbb1833a>] sysfs_kf_write+0x106/0x160 [<00000000d0dedb8a>] kernfs_fop_write_iter+0x3a8/0x5a0 [<00000000770b66e2>] vfs_write+0x8f0/0xc80 [<0000000078bb39be>] ksys_write+0x106/0x210 [<00000000005e55a4>] do_syscall_64+0x35/0x80 [<00000000eaa40bbc>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
CVE-2023-54048 1 Linux 1 Linux Kernel 2025-12-29 7.0 High
In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: Prevent handling any completions after qp destroy HW may generate completions that indicates QP is destroyed. Driver should not be scheduling any more completion handlers for this QP, after the QP is destroyed. Since CQs are active during the QP destroy, driver may still schedule completion handlers. This can cause a race where the destroy_cq and poll_cq running simultaneously. Snippet of kernel panic while doing bnxt_re driver load unload in loop. This indicates a poll after the CQ is freed.  [77786.481636] Call Trace: [77786.481640]  <TASK> [77786.481644]  bnxt_re_poll_cq+0x14a/0x620 [bnxt_re] [77786.481658]  ? kvm_clock_read+0x14/0x30 [77786.481693]  __ib_process_cq+0x57/0x190 [ib_core] [77786.481728]  ib_cq_poll_work+0x26/0x80 [ib_core] [77786.481761]  process_one_work+0x1e5/0x3f0 [77786.481768]  worker_thread+0x50/0x3a0 [77786.481785]  ? __pfx_worker_thread+0x10/0x10 [77786.481790]  kthread+0xe2/0x110 [77786.481794]  ? __pfx_kthread+0x10/0x10 [77786.481797]  ret_from_fork+0x2c/0x50 To avoid this, complete all completion handlers before returning the destroy QP. If free_cq is called soon after destroy_qp, IB stack will cancel the CQ work before invoking the destroy_cq verb and this will prevent any race mentioned.
CVE-2022-50731 1 Linux 1 Linux Kernel 2025-12-29 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: crypto: akcipher - default implementation for setting a private key Changes from v1: * removed the default implementation from set_pub_key: it is assumed that an implementation must always have this callback defined as there are no use case for an algorithm, which doesn't need a public key Many akcipher implementations (like ECDSA) support only signature verifications, so they don't have all callbacks defined. Commit 78a0324f4a53 ("crypto: akcipher - default implementations for request callbacks") introduced default callbacks for sign/verify operations, which just return an error code. However, these are not enough, because before calling sign the caller would likely call set_priv_key first on the instantiated transform (as the in-kernel testmgr does). This function does not have a default stub, so the kernel crashes, when trying to set a private key on an akcipher, which doesn't support signature generation. I've noticed this, when trying to add a KAT vector for ECDSA signature to the testmgr. With this patch the testmgr returns an error in dmesg (as it should) instead of crashing the kernel NULL ptr dereference.
CVE-2023-54067 1 Linux 1 Linux Kernel 2025-12-29 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix race when deleting free space root from the dirty cow roots list When deleting the free space tree we are deleting the free space root from the list fs_info->dirty_cowonly_roots without taking the lock that protects it, which is struct btrfs_fs_info::trans_lock. This unsynchronized list manipulation may cause chaos if there's another concurrent manipulation of this list, such as when adding a root to it with ctree.c:add_root_to_dirty_list(). This can result in all sorts of weird failures caused by a race, such as the following crash: [337571.278245] general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] PREEMPT SMP PTI [337571.278933] CPU: 1 PID: 115447 Comm: btrfs Tainted: G W 6.4.0-rc6-btrfs-next-134+ #1 [337571.279153] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [337571.279572] RIP: 0010:commit_cowonly_roots+0x11f/0x250 [btrfs] [337571.279928] Code: 85 38 06 00 (...) [337571.280363] RSP: 0018:ffff9f63446efba0 EFLAGS: 00010206 [337571.280582] RAX: ffff942d98ec2638 RBX: ffff9430b82b4c30 RCX: 0000000449e1c000 [337571.280798] RDX: dead000000000100 RSI: ffff9430021e4900 RDI: 0000000000036070 [337571.281015] RBP: ffff942d98ec2000 R08: ffff942d98ec2000 R09: 000000000000015b [337571.281254] R10: 0000000000000009 R11: 0000000000000001 R12: ffff942fe8fbf600 [337571.281476] R13: ffff942dabe23040 R14: ffff942dabe20800 R15: ffff942d92cf3b48 [337571.281723] FS: 00007f478adb7340(0000) GS:ffff94349fa40000(0000) knlGS:0000000000000000 [337571.281950] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [337571.282184] CR2: 00007f478ab9a3d5 CR3: 000000001e02c001 CR4: 0000000000370ee0 [337571.282416] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [337571.282647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [337571.282874] Call Trace: [337571.283101] <TASK> [337571.283327] ? __die_body+0x1b/0x60 [337571.283570] ? die_addr+0x39/0x60 [337571.283796] ? exc_general_protection+0x22e/0x430 [337571.284022] ? asm_exc_general_protection+0x22/0x30 [337571.284251] ? commit_cowonly_roots+0x11f/0x250 [btrfs] [337571.284531] btrfs_commit_transaction+0x42e/0xf90 [btrfs] [337571.284803] ? _raw_spin_unlock+0x15/0x30 [337571.285031] ? release_extent_buffer+0x103/0x130 [btrfs] [337571.285305] reset_balance_state+0x152/0x1b0 [btrfs] [337571.285578] btrfs_balance+0xa50/0x11e0 [btrfs] [337571.285864] ? __kmem_cache_alloc_node+0x14a/0x410 [337571.286086] btrfs_ioctl+0x249a/0x3320 [btrfs] [337571.286358] ? mod_objcg_state+0xd2/0x360 [337571.286577] ? refill_obj_stock+0xb0/0x160 [337571.286798] ? seq_release+0x25/0x30 [337571.287016] ? __rseq_handle_notify_resume+0x3ba/0x4b0 [337571.287235] ? percpu_counter_add_batch+0x2e/0xa0 [337571.287455] ? __x64_sys_ioctl+0x88/0xc0 [337571.287675] __x64_sys_ioctl+0x88/0xc0 [337571.287901] do_syscall_64+0x38/0x90 [337571.288126] entry_SYSCALL_64_after_hwframe+0x72/0xdc [337571.288352] RIP: 0033:0x7f478aaffe9b So fix this by locking struct btrfs_fs_info::trans_lock before deleting the free space root from that list.
CVE-2025-68734 1 Linux 1 Linux Kernel 2025-12-29 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: isdn: mISDN: hfcsusb: fix memory leak in hfcsusb_probe() In hfcsusb_probe(), the memory allocated for ctrl_urb gets leaked when setup_instance() fails with an error code. Fix that by freeing the urb before freeing the hw structure. Also change the error paths to use the goto ladder style. Compile tested only. Issue found using a prototype static analysis tool.
CVE-2022-50759 1 Linux 1 Linux Kernel 2025-12-29 N/A
In the Linux kernel, the following vulnerability has been resolved: media: i2c: ov5648: Free V4L2 fwnode data on unbind The V4L2 fwnode data structure doesn't get freed on unbind, which leads to a memleak.
CVE-2023-54104 1 Linux 1 Linux Kernel 2025-12-29 N/A
In the Linux kernel, the following vulnerability has been resolved: mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op() 'op-cs' is copied in 'fun->mchip_number' which is used to access the 'mchip_offsets' and the 'rnb_gpio' arrays. These arrays have NAND_MAX_CHIPS elements, so the index must be below this limit. Fix the sanity check in order to avoid the NAND_MAX_CHIPS value. This would lead to out-of-bound accesses.
CVE-2023-54106 1 Linux 1 Linux Kernel 2025-12-29 7.0 High
In the Linux kernel, the following vulnerability has been resolved: net/mlx5: fix potential memory leak in mlx5e_init_rep_rx The memory pointed to by the priv->rx_res pointer is not freed in the error path of mlx5e_init_rep_rx, which can lead to a memory leak. Fix by freeing the memory in the error path, thereby making the error path identical to mlx5e_cleanup_rep_rx().
CVE-2023-54116 1 Linux 1 Linux Kernel 2025-12-29 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: drm/fbdev-generic: prohibit potential out-of-bounds access The fbdev test of IGT may write after EOF, which lead to out-of-bound access for drm drivers with fbdev-generic. For example, run fbdev test on a x86+ast2400 platform, with 1680x1050 resolution, will cause the linux kernel hang with the following call trace: Oops: 0000 [#1] PREEMPT SMP PTI [IGT] fbdev: starting subtest eof Workqueue: events drm_fb_helper_damage_work [drm_kms_helper] [IGT] fbdev: starting subtest nullptr RIP: 0010:memcpy_erms+0xa/0x20 RSP: 0018:ffffa17d40167d98 EFLAGS: 00010246 RAX: ffffa17d4eb7fa80 RBX: ffffa17d40e0aa80 RCX: 00000000000014c0 RDX: 0000000000001a40 RSI: ffffa17d40e0b000 RDI: ffffa17d4eb80000 RBP: ffffa17d40167e20 R08: 0000000000000000 R09: ffff89522ecff8c0 R10: ffffa17d4e4c5000 R11: 0000000000000000 R12: ffffa17d4eb7fa80 R13: 0000000000001a40 R14: 000000000000041a R15: ffffa17d40167e30 FS: 0000000000000000(0000) GS:ffff895257380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffa17d40e0b000 CR3: 00000001eaeca006 CR4: 00000000001706e0 Call Trace: <TASK> ? drm_fbdev_generic_helper_fb_dirty+0x207/0x330 [drm_kms_helper] drm_fb_helper_damage_work+0x8f/0x170 [drm_kms_helper] process_one_work+0x21f/0x430 worker_thread+0x4e/0x3c0 ? __pfx_worker_thread+0x10/0x10 kthread+0xf4/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK> CR2: ffffa17d40e0b000 ---[ end trace 0000000000000000 ]--- The is because damage rectangles computed by drm_fb_helper_memory_range_to_clip() function is not guaranteed to be bound in the screen's active display area. Possible reasons are: 1) Buffers are allocated in the granularity of page size, for mmap system call support. The shadow screen buffer consumed by fbdev emulation may also choosed be page size aligned. 2) The DIV_ROUND_UP() used in drm_fb_helper_memory_range_to_clip() will introduce off-by-one error. For example, on a 16KB page size system, in order to store a 1920x1080 XRGB framebuffer, we need allocate 507 pages. Unfortunately, the size 1920*1080*4 can not be divided exactly by 16KB. 1920 * 1080 * 4 = 8294400 bytes 506 * 16 * 1024 = 8290304 bytes 507 * 16 * 1024 = 8306688 bytes line_length = 1920*4 = 7680 bytes 507 * 16 * 1024 / 7680 = 1081.6 off / line_length = 507 * 16 * 1024 / 7680 = 1081 DIV_ROUND_UP(507 * 16 * 1024, 7680) will yeild 1082 memcpy_toio() typically issue the copy line by line, when copy the last line, out-of-bound access will be happen. Because: 1082 * line_length = 1082 * 7680 = 8309760, and 8309760 > 8306688 Note that userspace may still write to the invisiable area if a larger buffer than width x stride is exposed. But it is not a big issue as long as there still have memory resolve the access if not drafting so far. - Also limit the y1 (Daniel) - keep fix patch it to minimal (Daniel) - screen_size is page size aligned because of it need mmap (Thomas) - Adding fixes tag (Thomas)
CVE-2023-54043 1 Linux 1 Linux Kernel 2025-12-29 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: iommufd: Do not add the same hwpt to the ioas->hwpt_list twice The hwpt is added to the hwpt_list only during its creation, it is never added again. This hunk is some missed leftover from rework. Adding it twice will corrupt the linked list in some cases. It effects HWPT specific attachment, which is something the test suite cannot cover until we can create a legitimate struct device with a non-system iommu "driver" (ie we need the bus removed from the iommu code)
CVE-2022-50718 1 Linux 1 Linux Kernel 2025-12-29 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix pci device refcount leak As comment of pci_get_domain_bus_and_slot() says, it returns a pci device with refcount increment, when finish using it, the caller must decrement the reference count by calling pci_dev_put(). So before returning from amdgpu_device_resume|suspend_display_audio(), pci_dev_put() is called to avoid refcount leak.
CVE-2022-50723 1 Linux 1 Linux Kernel 2025-12-29 7.0 High
In the Linux kernel, the following vulnerability has been resolved: bnxt_en: fix memory leak in bnxt_nvm_test() Free the kzalloc'ed buffer before returning in the success path.
CVE-2022-50734 1 Linux 1 Linux Kernel 2025-12-29 N/A
In the Linux kernel, the following vulnerability has been resolved: nvmem: core: Fix memleak in nvmem_register() dev_set_name will alloc memory for nvmem->dev.kobj.name in nvmem_register, when nvmem_validate_keepouts failed, nvmem's memory will be freed and return, but nobody will free memory for nvmem->dev.kobj.name, there will be memleak, so moving nvmem_validate_keepouts() after device_register() and let the device core deal with cleaning name in error cases.
CVE-2022-50756 1 Linux 1 Linux Kernel 2025-12-29 7.0 High
In the Linux kernel, the following vulnerability has been resolved: nvme-pci: fix mempool alloc size Convert the max size to bytes to match the units of the divisor that calculates the worst-case number of PRP entries. The result is used to determine how many PRP Lists are required. The code was previously rounding this to 1 list, but we can require 2 in the worst case. In that scenario, the driver would corrupt memory beyond the size provided by the mempool. While unlikely to occur (you'd need a 4MB in exactly 127 phys segments on a queue that doesn't support SGLs), this memory corruption has been observed by kfence.
CVE-2022-50783 1 Linux 1 Linux Kernel 2025-12-29 7.0 High
In the Linux kernel, the following vulnerability has been resolved: mptcp: use proper req destructor for IPv6 Before, only the destructor from TCP request sock in IPv4 was called even if the subflow was IPv6. It is important to use the right destructor to avoid memory leaks with some advanced IPv6 features, e.g. when the request socks contain specific IPv6 options.
CVE-2022-50762 1 Linux 1 Linux Kernel 2025-12-29 N/A
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Avoid UBSAN error on true_sectors_per_clst() syzbot reported UBSAN error as below: [ 76.901829][ T6677] ================================================================================ [ 76.903908][ T6677] UBSAN: shift-out-of-bounds in fs/ntfs3/super.c:675:13 [ 76.905363][ T6677] shift exponent -247 is negative This patch avoid this error.
CVE-2023-54133 1 Linux 1 Linux Kernel 2025-12-29 N/A
In the Linux kernel, the following vulnerability has been resolved: nfp: clean mc addresses in application firmware when closing port When moving devices from one namespace to another, mc addresses are cleaned in software while not removed from application firmware. Thus the mc addresses are remained and will cause resource leak. Now use `__dev_mc_unsync` to clean mc addresses when closing port.