CVE-2026-93196

nvdimm: virtio_pmem: refcount requests for token lifetime

State: Published
Severity: 8.4 High
Published: Sep 17, 2026
Updated: Oct 30, 2026
Reserved: Sep 17, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

nvdimm: virtio_pmem: refcount requests for token lifetime

KASAN reports slab-use-after-free in __wake_up_common(): BUG: KASAN: slab-use-after-free in __wake_up_common+0x114/0x160 Read of size 8 at addr ffff88810fdcb710 by task swapper/0/0

CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.19.0-next-20260220-00006-g1eae5f204ec3 #4 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x6d/0xb0 print_report+0x170/0x4e2 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? __virt_addr_valid+0x1dc/0x380 kasan_report+0xbc/0xf0 ? __wake_up_common+0x114/0x160 ? __wake_up_common+0x114/0x160 __wake_up_common+0x114/0x160 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 __wake_up+0x36/0x60 virtio_pmem_host_ack+0x11d/0x3b0 ? sched_balance_domains+0x29f/0xb00 ? __pfx_virtio_pmem_host_ack+0x10/0x10 ? _raw_spin_lock_irqsave+0x98/0x100 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 vring_interrupt+0x1c9/0x5e0 ? __pfx_vp_interrupt+0x10/0x10 vp_vring_interrupt+0x87/0x100 ? __pfx_vp_interrupt+0x10/0x10 __handle_irq_event_percpu+0x17f/0x550 ? __pfx__raw_spin_lock+0x10/0x10 handle_irq_event+0xab/0x1c0 handle_fasteoi_irq+0x276/0xae0 __common_interrupt+0x65/0x130 common_interrupt+0x78/0xa0 </IRQ>

virtio_pmem_host_ack() wakes a request that has already been freed by the submitter.

This happens when the request token is still reachable via the virtqueue, but virtio_pmem_flush() returns and frees it.

Fix the token lifetime by refcounting struct virtio_pmem_request. virtio_pmem_flush() holds a submitter reference, and the virtqueue holds an extra reference once the request is queued. The completion path drops the virtqueue reference, and the submitter drops its reference before returning.

Scores

CVSS	Score	Vector	Source
3.1	8.4 High	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	6e84200c0a2994b991259d19450eee561029bf70 to before 71ac70fc7f95963eca9d1145a9b02b8fe149eb4fAffected 6e84200c0a2994b991259d19450eee561029bf70 to before 41b2025709ec104a07d15540399809ae5851246eAffected 6e84200c0a2994b991259d19450eee561029bf70 to before 4691c137e9cbe76137d730a26d663d900ac7279bAffected 6e84200c0a2994b991259d19450eee561029bf70 to before be072a5d5e35f4bdf2da22f600b5d6dc6c5ff491Affected 6e84200c0a2994b991259d19450eee561029bf70 to before b1e740b9156621afd4c4aa66257f4dde8df1febeAffected 6e84200c0a2994b991259d19450eee561029bf70 to before e57140944b5a47a7fd5a142faab29a02af040bc8Affected
LinuxLinux	5.3Affected before 5.3Not affected 6.1.191 through 6.1.Not affected 6.6.160 through 6.6.Not affected 6.12.112 through 6.12.Not affected 6.18.52 through 6.18.Not affected 7.2.6 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

6e84200c0a2994b991259d19450eee561029bf70 to before 71ac70fc7f95963eca9d1145a9b02b8fe149eb4fAffected
6e84200c0a2994b991259d19450eee561029bf70 to before 41b2025709ec104a07d15540399809ae5851246eAffected
6e84200c0a2994b991259d19450eee561029bf70 to before 4691c137e9cbe76137d730a26d663d900ac7279bAffected
6e84200c0a2994b991259d19450eee561029bf70 to before be072a5d5e35f4bdf2da22f600b5d6dc6c5ff491Affected
6e84200c0a2994b991259d19450eee561029bf70 to before b1e740b9156621afd4c4aa66257f4dde8df1febeAffected
6e84200c0a2994b991259d19450eee561029bf70 to before e57140944b5a47a7fd5a142faab29a02af040bc8Affected

LinuxLinux

5.3Affected
before 5.3Not affected
6.1.191 through 6.1.*Not affected
6.6.160 through 6.6.*Not affected
6.12.112 through 6.12.*Not affected
6.18.52 through 6.18.*Not affected
7.2.6 through 7.2.*Not affected
7.3 and laterNot affected

References

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