Filtered by vendor Debian Subscriptions
Filtered by product Debian Linux Subscriptions
Total 9349 CVE
CVE Vendors Products Updated CVSS v3.1
CVE-2025-37836 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-14 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: PCI: Fix reference leak in pci_register_host_bridge() If device_register() fails, call put_device() to give up the reference to avoid a memory leak, per the comment at device_register(). Found by code review. [bhelgaas: squash Dan Carpenter's double free fix from https://lore.kernel.org/r/db806a6c-a91b-4e5a-a84b-6b7e01bdac85@stanley.mountain]
CVE-2025-37840 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-14 7.8 High
In the Linux kernel, the following vulnerability has been resolved: mtd: rawnand: brcmnand: fix PM resume warning Fixed warning on PM resume as shown below caused due to uninitialized struct nand_operation that checks chip select field : WARN_ON(op->cs >= nanddev_ntargets(&chip->base) [ 14.588522] ------------[ cut here ]------------ [ 14.588529] WARNING: CPU: 0 PID: 1392 at drivers/mtd/nand/raw/internals.h:139 nand_reset_op+0x1e0/0x1f8 [ 14.588553] Modules linked in: bdc udc_core [ 14.588579] CPU: 0 UID: 0 PID: 1392 Comm: rtcwake Tainted: G W 6.14.0-rc4-g5394eea10651 #16 [ 14.588590] Tainted: [W]=WARN [ 14.588593] Hardware name: Broadcom STB (Flattened Device Tree) [ 14.588598] Call trace: [ 14.588604] dump_backtrace from show_stack+0x18/0x1c [ 14.588622] r7:00000009 r6:0000008b r5:60000153 r4:c0fa558c [ 14.588625] show_stack from dump_stack_lvl+0x70/0x7c [ 14.588639] dump_stack_lvl from dump_stack+0x18/0x1c [ 14.588653] r5:c08d40b0 r4:c1003cb0 [ 14.588656] dump_stack from __warn+0x84/0xe4 [ 14.588668] __warn from warn_slowpath_fmt+0x18c/0x194 [ 14.588678] r7:c08d40b0 r6:c1003cb0 r5:00000000 r4:00000000 [ 14.588681] warn_slowpath_fmt from nand_reset_op+0x1e0/0x1f8 [ 14.588695] r8:70c40dff r7:89705f41 r6:36b4a597 r5:c26c9444 r4:c26b0048 [ 14.588697] nand_reset_op from brcmnand_resume+0x13c/0x150 [ 14.588714] r9:00000000 r8:00000000 r7:c24f8010 r6:c228a3f8 r5:c26c94bc r4:c26b0040 [ 14.588717] brcmnand_resume from platform_pm_resume+0x34/0x54 [ 14.588735] r5:00000010 r4:c0840a50 [ 14.588738] platform_pm_resume from dpm_run_callback+0x5c/0x14c [ 14.588757] dpm_run_callback from device_resume+0xc0/0x324 [ 14.588776] r9:c24f8054 r8:c24f80a0 r7:00000000 r6:00000000 r5:00000010 r4:c24f8010 [ 14.588779] device_resume from dpm_resume+0x130/0x160 [ 14.588799] r9:c22539e4 r8:00000010 r7:c22bebb0 r6:c24f8010 r5:c22539dc r4:c22539b0 [ 14.588802] dpm_resume from dpm_resume_end+0x14/0x20 [ 14.588822] r10:c2204e40 r9:00000000 r8:c228a3fc r7:00000000 r6:00000003 r5:c228a414 [ 14.588826] r4:00000010 [ 14.588828] dpm_resume_end from suspend_devices_and_enter+0x274/0x6f8 [ 14.588848] r5:c228a414 r4:00000000 [ 14.588851] suspend_devices_and_enter from pm_suspend+0x228/0x2bc [ 14.588868] r10:c3502910 r9:c3501f40 r8:00000004 r7:c228a438 r6:c0f95e18 r5:00000000 [ 14.588871] r4:00000003 [ 14.588874] pm_suspend from state_store+0x74/0xd0 [ 14.588889] r7:c228a438 r6:c0f934c8 r5:00000003 r4:00000003 [ 14.588892] state_store from kobj_attr_store+0x1c/0x28 [ 14.588913] r9:00000000 r8:00000000 r7:f09f9f08 r6:00000004 r5:c3502900 r4:c0283250 [ 14.588916] kobj_attr_store from sysfs_kf_write+0x40/0x4c [ 14.588936] r5:c3502900 r4:c0d92a48 [ 14.588939] sysfs_kf_write from kernfs_fop_write_iter+0x104/0x1f0 [ 14.588956] r5:c3502900 r4:c3501f40 [ 14.588960] kernfs_fop_write_iter from vfs_write+0x250/0x420 [ 14.588980] r10:c0e14b48 r9:00000000 r8:c25f5780 r7:00443398 r6:f09f9f68 r5:c34f7f00 [ 14.588983] r4:c042a88c [ 14.588987] vfs_write from ksys_write+0x74/0xe4 [ 14.589005] r10:00000004 r9:c25f5780 r8:c02002fA0 r7:00000000 r6:00000000 r5:c34f7f00 [ 14.589008] r4:c34f7f00 [ 14.589011] ksys_write from sys_write+0x10/0x14 [ 14.589029] r7:00000004 r6:004421c0 r5:00443398 r4:00000004 [ 14.589032] sys_write from ret_fast_syscall+0x0/0x5c [ 14.589044] Exception stack(0xf09f9fa8 to 0xf09f9ff0) [ 14.589050] 9fa0: 00000004 00443398 00000004 00443398 00000004 00000001 [ 14.589056] 9fc0: 00000004 00443398 004421c0 00000004 b6ecbd58 00000008 bebfbc38 0043eb78 [ 14.589062] 9fe0: 00440eb0 bebfbaf8 b6de18a0 b6e579e8 [ 14.589065] ---[ end trace 0000000000000000 ]--- The fix uses the higher level nand_reset(chip, chipnr); where chipnr = 0, when doing PM resume operation in compliance with the controller support for single die nand chip. Switching from nand_reset_op() to nan ---truncated---
CVE-2021-47247 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-14 7.8 High
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix use-after-free of encap entry in neigh update handler Function mlx5e_rep_neigh_update() wasn't updated to accommodate rtnl lock removal from TC filter update path and properly handle concurrent encap entry insertion/deletion which can lead to following use-after-free: [23827.464923] ================================================================== [23827.469446] BUG: KASAN: use-after-free in mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.470971] Read of size 4 at addr ffff8881d132228c by task kworker/u20:6/21635 [23827.472251] [23827.472615] CPU: 9 PID: 21635 Comm: kworker/u20:6 Not tainted 5.13.0-rc3+ #5 [23827.473788] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [23827.475639] Workqueue: mlx5e mlx5e_rep_neigh_update [mlx5_core] [23827.476731] Call Trace: [23827.477260] dump_stack+0xbb/0x107 [23827.477906] print_address_description.constprop.0+0x18/0x140 [23827.478896] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.479879] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.480905] kasan_report.cold+0x7c/0xd8 [23827.481701] ? mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.482744] kasan_check_range+0x145/0x1a0 [23827.493112] mlx5e_encap_take+0x72/0x140 [mlx5_core] [23827.494054] ? mlx5e_tc_tun_encap_info_equal_generic+0x140/0x140 [mlx5_core] [23827.495296] mlx5e_rep_neigh_update+0x41e/0x5e0 [mlx5_core] [23827.496338] ? mlx5e_rep_neigh_entry_release+0xb80/0xb80 [mlx5_core] [23827.497486] ? read_word_at_a_time+0xe/0x20 [23827.498250] ? strscpy+0xa0/0x2a0 [23827.498889] process_one_work+0x8ac/0x14e0 [23827.499638] ? lockdep_hardirqs_on_prepare+0x400/0x400 [23827.500537] ? pwq_dec_nr_in_flight+0x2c0/0x2c0 [23827.501359] ? rwlock_bug.part.0+0x90/0x90 [23827.502116] worker_thread+0x53b/0x1220 [23827.502831] ? process_one_work+0x14e0/0x14e0 [23827.503627] kthread+0x328/0x3f0 [23827.504254] ? _raw_spin_unlock_irq+0x24/0x40 [23827.505065] ? __kthread_bind_mask+0x90/0x90 [23827.505912] ret_from_fork+0x1f/0x30 [23827.506621] [23827.506987] Allocated by task 28248: [23827.507694] kasan_save_stack+0x1b/0x40 [23827.508476] __kasan_kmalloc+0x7c/0x90 [23827.509197] mlx5e_attach_encap+0xde1/0x1d40 [mlx5_core] [23827.510194] mlx5e_tc_add_fdb_flow+0x397/0xc40 [mlx5_core] [23827.511218] __mlx5e_add_fdb_flow+0x519/0xb30 [mlx5_core] [23827.512234] mlx5e_configure_flower+0x191c/0x4870 [mlx5_core] [23827.513298] tc_setup_cb_add+0x1d5/0x420 [23827.514023] fl_hw_replace_filter+0x382/0x6a0 [cls_flower] [23827.514975] fl_change+0x2ceb/0x4a51 [cls_flower] [23827.515821] tc_new_tfilter+0x89a/0x2070 [23827.516548] rtnetlink_rcv_msg+0x644/0x8c0 [23827.517300] netlink_rcv_skb+0x11d/0x340 [23827.518021] netlink_unicast+0x42b/0x700 [23827.518742] netlink_sendmsg+0x743/0xc20 [23827.519467] sock_sendmsg+0xb2/0xe0 [23827.520131] ____sys_sendmsg+0x590/0x770 [23827.520851] ___sys_sendmsg+0xd8/0x160 [23827.521552] __sys_sendmsg+0xb7/0x140 [23827.522238] do_syscall_64+0x3a/0x70 [23827.522907] entry_SYSCALL_64_after_hwframe+0x44/0xae [23827.523797] [23827.524163] Freed by task 25948: [23827.524780] kasan_save_stack+0x1b/0x40 [23827.525488] kasan_set_track+0x1c/0x30 [23827.526187] kasan_set_free_info+0x20/0x30 [23827.526968] __kasan_slab_free+0xed/0x130 [23827.527709] slab_free_freelist_hook+0xcf/0x1d0 [23827.528528] kmem_cache_free_bulk+0x33a/0x6e0 [23827.529317] kfree_rcu_work+0x55f/0xb70 [23827.530024] process_one_work+0x8ac/0x14e0 [23827.530770] worker_thread+0x53b/0x1220 [23827.531480] kthread+0x328/0x3f0 [23827.532114] ret_from_fork+0x1f/0x30 [23827.532785] [23827.533147] Last potentially related work creation: [23827.534007] kasan_save_stack+0x1b/0x40 [23827.534710] kasan_record_aux_stack+0xab/0xc0 [23827.535492] kvfree_call_rcu+0x31/0x7b0 [23827.536206] mlx5e_tc_del ---truncated---
CVE-2024-36913 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-14 8.1 High
In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: vmbus: Leak pages if set_memory_encrypted() fails In CoCo VMs it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues. VMBus code could free decrypted pages if set_memory_encrypted()/decrypted() fails. Leak the pages if this happens.
CVE-2023-4194 4 Debian, Fedoraproject, Linux and 1 more 5 Debian Linux, Fedora, Linux Kernel and 2 more 2025-11-14 5.5 Medium
A flaw was found in the Linux kernel's TUN/TAP functionality. This issue could allow a local user to bypass network filters and gain unauthorized access to some resources. The original patches fixing CVE-2023-1076 are incorrect or incomplete. The problem is that the following upstream commits - a096ccca6e50 ("tun: tun_chr_open(): correctly initialize socket uid"), - 66b2c338adce ("tap: tap_open(): correctly initialize socket uid"), pass "inode->i_uid" to sock_init_data_uid() as the last parameter and that turns out to not be accurate.
CVE-2023-4273 5 Debian, Fedoraproject, Linux and 2 more 12 Debian Linux, Fedora, Linux Kernel and 9 more 2025-11-14 6 Medium
A flaw was found in the exFAT driver of the Linux kernel. The vulnerability exists in the implementation of the file name reconstruction function, which is responsible for reading file name entries from a directory index and merging file name parts belonging to one file into a single long file name. Since the file name characters are copied into a stack variable, a local privileged attacker could use this flaw to overflow the kernel stack.
CVE-2023-3773 4 Debian, Fedoraproject, Linux and 1 more 4 Debian Linux, Fedora, Linux Kernel and 1 more 2025-11-14 5.5 Medium
A flaw was found in the Linux kernel’s IP framework for transforming packets (XFRM subsystem). This issue may allow a malicious user with CAP_NET_ADMIN privileges to cause a 4 byte out-of-bounds read of XFRMA_MTIMER_THRESH when parsing netlink attributes, leading to potential leakage of sensitive heap data to userspace.
CVE-2025-24201 3 Apple, Debian, Redhat 13 Ipados, Iphone Os, Macos and 10 more 2025-11-14 10 Critical
An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in visionOS 2.3.2, iOS 18.3.2 and iPadOS 18.3.2, macOS Sequoia 15.3.2, Safari 18.3.1, watchOS 11.4, iPadOS 17.7.6, iOS 16.7.11 and iPadOS 16.7.11, iOS 15.8.4 and iPadOS 15.8.4. Maliciously crafted web content may be able to break out of Web Content sandbox. This is a supplementary fix for an attack that was blocked in iOS 17.2. (Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals on versions of iOS before iOS 17.2.).
CVE-2025-37829 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: cpufreq: scpi: Fix null-ptr-deref in scpi_cpufreq_get_rate() cpufreq_cpu_get_raw() can return NULL when the target CPU is not present in the policy->cpus mask. scpi_cpufreq_get_rate() does not check for this case, which results in a NULL pointer dereference.
CVE-2025-37830 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: cpufreq: scmi: Fix null-ptr-deref in scmi_cpufreq_get_rate() cpufreq_cpu_get_raw() can return NULL when the target CPU is not present in the policy->cpus mask. scmi_cpufreq_get_rate() does not check for this case, which results in a NULL pointer dereference. Add NULL check after cpufreq_cpu_get_raw() to prevent this issue.
CVE-2025-37810 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 7.8 High
In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: check that event count does not exceed event buffer length The event count is read from register DWC3_GEVNTCOUNT. There is a check for the count being zero, but not for exceeding the event buffer length. Check that event count does not exceed event buffer length, avoiding an out-of-bounds access when memcpy'ing the event. Crash log: Unable to handle kernel paging request at virtual address ffffffc0129be000 pc : __memcpy+0x114/0x180 lr : dwc3_check_event_buf+0xec/0x348 x3 : 0000000000000030 x2 : 000000000000dfc4 x1 : ffffffc0129be000 x0 : ffffff87aad60080 Call trace: __memcpy+0x114/0x180 dwc3_interrupt+0x24/0x34
CVE-2025-37811 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: usb: chipidea: ci_hdrc_imx: fix usbmisc handling usbmisc is an optional device property so it is totally valid for the corresponding data->usbmisc_data to have a NULL value. Check that before dereferencing the pointer. Found by Linux Verification Center (linuxtesting.org) with Svace static analysis tool.
CVE-2025-37812 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: usb: cdns3: Fix deadlock when using NCM gadget The cdns3 driver has the same NCM deadlock as fixed in cdnsp by commit 58f2fcb3a845 ("usb: cdnsp: Fix deadlock issue during using NCM gadget"). Under PREEMPT_RT the deadlock can be readily triggered by heavy network traffic, for example using "iperf --bidir" over NCM ethernet link. The deadlock occurs because the threaded interrupt handler gets preempted by a softirq, but both are protected by the same spinlock. Prevent deadlock by disabling softirq during threaded irq handler.
CVE-2025-37817 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 7.8 High
In the Linux kernel, the following vulnerability has been resolved: mcb: fix a double free bug in chameleon_parse_gdd() In chameleon_parse_gdd(), if mcb_device_register() fails, 'mdev' would be released in mcb_device_register() via put_device(). Thus, goto 'err' label and free 'mdev' again causes a double free. Just return if mcb_device_register() fails.
CVE-2025-37818 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: LoongArch: Return NULL from huge_pte_offset() for invalid PMD LoongArch's huge_pte_offset() currently returns a pointer to a PMD slot even if the underlying entry points to invalid_pte_table (indicating no mapping). Callers like smaps_hugetlb_range() fetch this invalid entry value (the address of invalid_pte_table) via this pointer. The generic is_swap_pte() check then incorrectly identifies this address as a swap entry on LoongArch, because it satisfies the "!pte_present() && !pte_none()" conditions. This misinterpretation, combined with a coincidental match by is_migration_entry() on the address bits, leads to kernel crashes in pfn_swap_entry_to_page(). Fix this at the architecture level by modifying huge_pte_offset() to check the PMD entry's content using pmd_none() before returning. If the entry is invalid (i.e., it points to invalid_pte_table), return NULL instead of the pointer to the slot.
CVE-2025-37819 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 7.8 High
In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v2m: Prevent use after free of gicv2m_get_fwnode() With ACPI in place, gicv2m_get_fwnode() is registered with the pci subsystem as pci_msi_get_fwnode_cb(), which may get invoked at runtime during a PCI host bridge probe. But, the call back is wrongly marked as __init, causing it to be freed, while being registered with the PCI subsystem and could trigger: Unable to handle kernel paging request at virtual address ffff8000816c0400 gicv2m_get_fwnode+0x0/0x58 (P) pci_set_bus_msi_domain+0x74/0x88 pci_register_host_bridge+0x194/0x548 This is easily reproducible on a Juno board with ACPI boot. Retain the function for later use.
CVE-2025-37820 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: xen-netfront: handle NULL returned by xdp_convert_buff_to_frame() The function xdp_convert_buff_to_frame() may return NULL if it fails to correctly convert the XDP buffer into an XDP frame due to memory constraints, internal errors, or invalid data. Failing to check for NULL may lead to a NULL pointer dereference if the result is used later in processing, potentially causing crashes, data corruption, or undefined behavior. On XDP redirect failure, the associated page must be released explicitly if it was previously retained via get_page(). Failing to do so may result in a memory leak, as the pages reference count is not decremented.
CVE-2025-37892 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 7.8 High
In the Linux kernel, the following vulnerability has been resolved: mtd: inftlcore: Add error check for inftl_read_oob() In INFTL_findwriteunit(), the return value of inftl_read_oob() need to be checked. A proper implementation can be found in INFTL_deleteblock(). The status will be set as SECTOR_IGNORE to break from the while-loop correctly if the inftl_read_oob() fails.
CVE-2025-37867 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Silence oversized kvmalloc() warning syzkaller triggered an oversized kvmalloc() warning. Silence it by adding __GFP_NOWARN. syzkaller log: WARNING: CPU: 7 PID: 518 at mm/util.c:665 __kvmalloc_node_noprof+0x175/0x180 CPU: 7 UID: 0 PID: 518 Comm: c_repro Not tainted 6.11.0-rc6+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:__kvmalloc_node_noprof+0x175/0x180 RSP: 0018:ffffc90001e67c10 EFLAGS: 00010246 RAX: 0000000000000100 RBX: 0000000000000400 RCX: ffffffff8149d46b RDX: 0000000000000000 RSI: ffff8881030fae80 RDI: 0000000000000002 RBP: 000000712c800000 R08: 0000000000000100 R09: 0000000000000000 R10: ffffc90001e67c10 R11: 0030ae0601000000 R12: 0000000000000000 R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007fde79159740(0000) GS:ffff88813bdc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000180 CR3: 0000000105eb4005 CR4: 00000000003706b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ib_umem_odp_get+0x1f6/0x390 mlx5_ib_reg_user_mr+0x1e8/0x450 ib_uverbs_reg_mr+0x28b/0x440 ib_uverbs_write+0x7d3/0xa30 vfs_write+0x1ac/0x6c0 ksys_write+0x134/0x170 ? __sanitizer_cov_trace_pc+0x1c/0x50 do_syscall_64+0x50/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e
CVE-2025-37865 2 Debian, Linux 2 Debian Linux, Linux Kernel 2025-11-12 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: net: dsa: mv88e6xxx: fix -ENOENT when deleting VLANs and MST is unsupported Russell King reports that on the ZII dev rev B, deleting a bridge VLAN from a user port fails with -ENOENT: https://lore.kernel.org/netdev/Z_lQXNP0s5-IiJzd@shell.armlinux.org.uk/ This comes from mv88e6xxx_port_vlan_leave() -> mv88e6xxx_mst_put(), which tries to find an MST entry in &chip->msts associated with the SID, but fails and returns -ENOENT as such. But we know that this chip does not support MST at all, so that is not surprising. The question is why does the guard in mv88e6xxx_mst_put() not exit early: if (!sid) return 0; And the answer seems to be simple: the sid comes from vlan.sid which supposedly was previously populated by mv88e6xxx_vtu_get(). But some chip->info->ops->vtu_getnext() implementations do not populate vlan.sid, for example see mv88e6185_g1_vtu_getnext(). In that case, later in mv88e6xxx_port_vlan_leave() we are using a garbage sid which is just residual stack memory. Testing for sid == 0 covers all cases of a non-bridge VLAN or a bridge VLAN mapped to the default MSTI. For some chips, SID 0 is valid and installed by mv88e6xxx_stu_setup(). A chip which does not support the STU would implicitly only support mapping all VLANs to the default MSTI, so although SID 0 is not valid, it would be sufficient, if we were to zero-initialize the vlan structure, to fix the bug, due to the coincidence that a test for vlan.sid == 0 already exists and leads to the same (correct) behavior. Another option which would be sufficient would be to add a test for mv88e6xxx_has_stu() inside mv88e6xxx_mst_put(), symmetric to the one which already exists in mv88e6xxx_mst_get(). But that placement means the caller will have to dereference vlan.sid, which means it will access uninitialized memory, which is not nice even if it ignores it later. So we end up making both modifications, in order to not rely just on the sid == 0 coincidence, but also to avoid having uninitialized structure fields which might get temporarily accessed.