CVE-2026-98259
Low risk· EPSS 5%Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
A vulnerability in the Linux kernel's fs/dax subsystem can cause a kernel panic during VM boot with DAX-enabled storage. The issue is the lack of a check for empty or zero entries in the xarray before calling dax_to_folio() in dax_associate_entry(), dax_disassociate_entry(), and dax_busy_page(). A previous fix (commit 98c183a4fccf) added guards but they still come after dax_to_folio(), leaving the problem unresolved.
Risk Assessment
The vulnerability can cause a system crash (kernel panic) during DAX file operations, leading to service unavailability and potential data loss. A local attacker could intentionally trigger the panic by mounting a specially crafted filesystem, resulting in a denial of service.
Recommendation
Immediately update the Linux kernel to a version containing the fix that checks for empty entries before calling dax_to_folio(). If updating is not possible, restrict access to DAX filesystems or disable DAX support in the kernel configuration.
Other vulnerabilities in Linux kernel
See all- CVE-2026-99259Unknown
In the Linux kernel, the soc/tegra: pmc driver has an uninitialised early_pmc->rate variable for legacy 32-bit Tegra devices. The variable is never configured and remains 0, triggering a warning in tegra_pmc_enter_suspend_mode(). The issue appeared after the PMC driver was changed to create the PMC context dynamically, updating rate only in the new context.
- 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
In the Linux kernel, the i2c: xiic driver was changed to restore non-managed runtime PM instead of the devres-based approach to fix a clk WARN flood. The managed release tore down runtime PM in the wrong order, causing the clock to be disabled twice and triggering "clkN already disabled" warnings on every teardown.
- CVE-2026-99247Unknown
In the Linux kernel, if trace buffer allocation fails during early boot, tracing_disabled remains set and the global trace array events list stays uninitialized. tracer_init_tracefs_work_func() runs asynchronously without checking this state and calls event_trace_init() and init_tracer_tracefs(), leading to a NULL pointer dereference Oops during boot. The fix checks tracing_disabled at the start of the work function.
- 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: fs/dax: check zero or empty entry before converting xarray entry Calling dax_to_folio() with empty entry causes kernel panic below when booting a VM with DAX enabled storage. This patch checks empty entry before calling dax_to_folio() on dax_associate_entry(), dax_disassociate_entry(), and dax_busy_page(). Commit 98c183a4fccf ("fs/dax: don't disassociate zero page entries") added guards in the associate and disassociate paths, but the guards still come after dax_to_folio(), and dax_busy_page() still has the same problem. [ 0.737679] EXT4-fs (pmem0p1): mounted filesystem 79676804-7c8b-491a-b2a6-9bae3c72af70 ro with ordered data mode. Quota mode: disabled. [ 0.737891] VFS: Mounted root (ext4 filesystem) readonly on device 259:1. [ 0.739119] devtmpfs: mounted [ 0.739476] Freeing unused kernel memory: 1920K [ 0.740156] Run /sbin/init as init process [ 0.740229] with arguments: [ 0.740286] /sbin/init [ 0.740321] with environment: [ 0.740369] HOME=/ [ 0.740400] TERM=linux [ 0.743162] Unable to handle kernel paging request at virtual address fffffdffbf000008 [ 0.743285] Mem abort info: [ 0.743316] ESR = 0x0000000096000006 [ 0.743371] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.743444] SET = 0, FnV = 0 [ 0.743489] EA = 0, S1PTW = 0 [ 0.743545] FSC = 0x06: level 2 translation fault [ 0.743610] Data abort info: [ 0.743656] ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000 [ 0.743720] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 0.743785] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 0.743848] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000b9d17000 [ 0.743931] [fffffdffbf000008] pgd=10000000bfa3d403, p4d=10000000bfa3d403, pud=1000000040bfe403, pmd=0000000000000000 [ 0.744070] Internal error: Oops: 0000000096000006 [#1] SMP [ 0.748888] CPU: 0 UID: 0 PID: 1 Comm: init Not tainted 6.18.4 #1 NONE [ 0.749421] pstate: 004000c5 (nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.749969] pc : dax_disassociate_entry.constprop.0+0x20/0x50 [ 0.750444] lr : dax_insert_entry+0xcc/0x408 [ 0.750802] sp : ffff80008000b9e0 [ 0.751083] x29: ffff80008000b9e0 x28: 0000000000000000 x27: 0000000000000000 [ 0.751682] x26: 0000000001963d01 x25: ffff0000004f7d90 x24: 0000000000000000 [ 0.752264] x23: 0000000000000000 x22: ffff80008000bcc8 x21: 0000000000000011 [ 0.752836] x20: ffff80008000ba90 x19: 0000000001963d01 x18: 0000000000000000 [ 0.753407] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 0.753970] x14: ffffbf3154b9ae70 x13: 0000000000000000 x12: ffffbf3154b9ae70 [ 0.754548] x11: ffffffffffffffff x10: 0000000000000000 x9 : 0000000000000000 [ 0.755122] x8 : 000000000000000d x7 : 000000000000001f x6 : 0000000000000000 [ 0.755707] x5 : 0000000000000000 x4 : 0000000000000000 x3 : fffffdffc0000000 [ 0.756287] x2 : 0000000000000008 x1 : 0000000040000000 x0 : fffffdffbf000000 [ 0.756871] Call trace: [ 0.757107] dax_disassociate_entry.constprop.0+0x20/0x50 (P) [ 0.757592] dax_iomap_pte_fault+0x4fc/0x808 [ 0.757951] dax_iomap_fault+0x28/0x30 [ 0.758258] ext4_dax_huge_fault+0x80/0x2dc [ 0.758594] ext4_dax_fault+0x10/0x3c [ 0.758892] __do_fault+0x38/0x12c [ 0.759175] __handle_mm_fault+0x530/0xcf0 [ 0.759518] handle_mm_fault+0xe4/0x230 [ 0.759833] do_page_fault+0x17c/0x4dc [ 0.760144] do_translation_fault+0x30/0x38 [ 0.760483] do_mem_abort+0x40/0x8c [ 0.760771] el0_ia+0x4c/0x170 [ 0.761032] el0t_64_sync_handler+0xd8/0xdc [ 0.761371] el0t_64_sync+0x168/0x16c [ 0.761677] Code: f9453021 f2dfbfe3 cb813080 8b001860 (f9400401) [ 0.762168] ---[ end trace 0000000000000000 ]--- [ 0.762550] note: init[1] exited with irqs disabled [ 0.762631] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Vulnerability data from NVD (NIST) · CISA KEV · EPSS