CVE-2024-56566
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk13th percentile - higher than 13% of all known CVEs
Summary
In the Linux kernel, a list corruption occurs in mm/slub when removing a slab from the full list. If an allocated object fails consistency checks, the slab is marked as used and removed from the partial list; later, when an object from that slab is freed, remove_full() attempts to remove it from a list it is not on, causing list corruption and a kernel BUG. This affects SLUB debugging with slub_debug=UFPZ.
Risk Assessment
This can lead to a kernel panic (BUG) and system unavailability, especially in environments with SLUB debugging enabled. The bug requires specific conditions but results in a critical crash.
Recommendation
Update the Linux kernel to a version containing the fix (the commit that resolves this issue). Avoid using slub_debug=UFPZ in production unless necessary for debugging.
Other vulnerabilities in Linux kernel
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- CVE-2026-99258Unknown
In the Linux kernel, hv_apicid_to_vp_index() uses per-CPU hypercall input and output pages. In an SEV-SNP CoCo VM without a paravisor the output page is not allocated, so the hypervisor stores the resulting VP index into memory not allocated by the guest. The fix uses the input page for both input and output.
- CVE-2026-99257Unknown
In the Linux kernel, the shared GPIO mechanism based on platform lookup tables requires an associated struct device. An fwnode-based lookup with no associated device currently causes a NULL-pointer dereference. The fix adds a check that lets the kernel gracefully handle this situation with an error.
- CVE-2026-99256Unknown
In the Linux kernel, the dm cache module used a rw_semaphore for background_work_lock, although write locks on rw_semaphores have strict owner semantics. The locking process was not always the same as the unlocking one, triggering a warning with CONFIG_DEBUG_RWSEMS during suspend/resume of a cache device. The fix replaces the rw_semaphore with a spinlock and a wait queue.
- CVE-2026-99251Unknown
In the Linux kernel, init_vp_index() contains a retry loop that strips CPUs from a node if they are already in the allocated cpumask or outside the HK_TYPE_MANAGED_IRQ housekeeping cpumask. If the housekeeping cpumask contains no CPU in that node, the loop becomes infinite. The fix skips NUMA nodes with no housekeeping CPU and aborts early when no online housekeeping CPUs exist.
- CVE-2026-99250Unknown
In the Linux kernel, the NBCON console printing kthreads are started very early during boot via early_initcall(). Asynchronously enabling/disabling interrupts during early boot may interfere with early SMP setup on some hardware platforms, causing hangs. The fix postpones kthread startup until after all arch initcalls have completed.
- CVE-2026-99249Unknown
In the Linux kernel, zap_pid_ns_processes() waiting for PID namespace cleanup was not freezable. A tracer outside the namespace that does not reap its traced zombies keeps PIDs allocated, making the wait unbounded and causing every suspend attempt to fail. The fix makes the wait loops use TASK_FREEZABLE states so the freezer can freeze waiting tasks.
- CVE-2026-99248Unknown
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- CVE-2026-99247Unknown
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- CVE-2026-99215Unknown
In the Linux kernel power supply subsystem, a use-after-free vulnerability exists. If a power supply is unregistered while its external_power_changed() callback is still running, the driver may free data that the callback is still accessing, leading to a kernel crash (NULL pointer dereference).
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: mm/slub: Avoid list corruption when removing a slab from the full list Boot with slub_debug=UFPZ. If allocated object failed in alloc_consistency_checks, all objects of the slab will be marked as used, and then the slab will be removed from the partial list. When an object belonging to the slab got freed later, the remove_full() function is called. Because the slab is neither on the partial list nor on the full list, it eventually lead to a list corruption (actually a list poison being detected). So we need to mark and isolate the slab page with metadata corruption, do not put it back in circulation. Because the debug caches avoid all the fastpaths, reusing the frozen bit to mark slab page with metadata corruption seems to be fine. [ 4277.385669] list_del corruption, ffffea00044b3e50->next is LIST_POISON1 (dead000000000100) [ 4277.387023] ------------[ cut here ]------------ [ 4277.387880] kernel BUG at lib/list_debug.c:56! [ 4277.388680] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 4277.389562] CPU: 5 PID: 90 Comm: kworker/5:1 Kdump: loaded Tainted: G OE 6.6.1-1 #1 [ 4277.392113] Workqueue: xfs-inodegc/vda1 xfs_inodegc_worker [xfs] [ 4277.393551] RIP: 0010:__list_del_entry_valid_or_report+0x7b/0xc0 [ 4277.394518] Code: 48 91 82 e8 37 f9 9a ff 0f 0b 48 89 fe 48 c7 c7 28 49 91 82 e8 26 f9 9a ff 0f 0b 48 89 fe 48 c7 c7 58 49 91 [ 4277.397292] RSP: 0018:ffffc90000333b38 EFLAGS: 00010082 [ 4277.398202] RAX: 000000000000004e RBX: ffffea00044b3e50 RCX: 0000000000000000 [ 4277.399340] RDX: 0000000000000002 RSI: ffffffff828f8715 RDI: 00000000ffffffff [ 4277.400545] RBP: ffffea00044b3e40 R08: 0000000000000000 R09: ffffc900003339f0 [ 4277.401710] R10: 0000000000000003 R11: ffffffff82d44088 R12: ffff888112cf9910 [ 4277.402887] R13: 0000000000000001 R14: 0000000000000001 R15: ffff8881000424c0 [ 4277.404049] FS: 0000000000000000(0000) GS:ffff88842fd40000(0000) knlGS:0000000000000000 [ 4277.405357] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4277.406389] CR2: 00007f2ad0b24000 CR3: 0000000102a3a006 CR4: 00000000007706e0 [ 4277.407589] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 4277.408780] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 4277.410000] PKRU: 55555554 [ 4277.410645] Call Trace: [ 4277.411234] <TASK> [ 4277.411777] ? die+0x32/0x80 [ 4277.412439] ? do_trap+0xd6/0x100 [ 4277.413150] ? __list_del_entry_valid_or_report+0x7b/0xc0 [ 4277.414158] ? do_error_trap+0x6a/0x90 [ 4277.414948] ? __list_del_entry_valid_or_report+0x7b/0xc0 [ 4277.415915] ? exc_invalid_op+0x4c/0x60 [ 4277.416710] ? __list_del_entry_valid_or_report+0x7b/0xc0 [ 4277.417675] ? asm_exc_invalid_op+0x16/0x20 [ 4277.418482] ? __list_del_entry_valid_or_report+0x7b/0xc0 [ 4277.419466] ? __list_del_entry_valid_or_report+0x7b/0xc0 [ 4277.420410] free_to_partial_list+0x515/0x5e0 [ 4277.421242] ? xfs_iext_remove+0x41a/0xa10 [xfs] [ 4277.422298] xfs_iext_remove+0x41a/0xa10 [xfs] [ 4277.423316] ? xfs_inodegc_worker+0xb4/0x1a0 [xfs] [ 4277.424383] xfs_bmap_del_extent_delay+0x4fe/0x7d0 [xfs] [ 4277.425490] __xfs_bunmapi+0x50d/0x840 [xfs] [ 4277.426445] xfs_itruncate_extents_flags+0x13a/0x490 [xfs] [ 4277.427553] xfs_inactive_truncate+0xa3/0x120 [xfs] [ 4277.428567] xfs_inactive+0x22d/0x290 [xfs] [ 4277.429500] xfs_inodegc_worker+0xb4/0x1a0 [xfs] [ 4277.430479] process_one_work+0x171/0x340 [ 4277.431227] worker_thread+0x277/0x390 [ 4277.431962] ? __pfx_worker_thread+0x10/0x10 [ 4277.432752] kthread+0xf0/0x120 [ 4277.433382] ? __pfx_kthread+0x10/0x10 [ 4277.434134] ret_from_fork+0x2d/0x50 [ 4277.434837] ? __pfx_kthread+0x10/0x10 [ 4277.435566] ret_from_fork_asm+0x1b/0x30 [ 4277.436280] </TASK>
Vulnerability data from NVD (NIST) · CISA KEV · EPSS