CVE-2026-64207
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
In the Linux kernel, a bug in DualPI2 (net/sched) GSO segmentation accounting causes double counting in the parent queue. When QFQ is the parent, after all real packets are dequeued, the queue still has non-zero length, leading to a NULL pointer dereference.
Risk Assessment
An attacker can trigger a kernel panic (NULL pointer dereference) causing denial of service (DoS) on systems using DualPI2 with QFQ as the parent qdisc.
Recommendation
Update the Linux kernel to a version containing the fix (commit: 5a8c3f5e4b2c). If not possible, avoid using DualPI2 with QFQ as the parent qdisc as a temporary workaround.
Other vulnerabilities in Linux kernel
See all- CVE-2026-80577Unknown
In the Linux kernel's drm/panthor driver, panthor_fw_load_section_entry() skips BO creation for zero-sized firmware sections but adds them to the section list, leading to NULL pointer dereference in later paths. The fix skips adding such sections to the list.
- CVE-2026-80571Unknown
In the Linux kernel powerpc/pseries papr-phy-attest, missing validation of cmd.length could lead to buffer overflow. The fix adds length checks and fixes memory leaks on error paths.
- CVE-2026-80567Unknown
In the Linux kernel Synaptics RMI4 driver (F54), worker errors were not propagated to the V4L2 queue, causing stale or uninitialized data to be delivered to userspace. The fix adds error checking and marks buffers as error state.
- CVE-2026-80566Unknown
In the Linux kernel, the hynitron_cstxxx driver improperly validated touch count and finger IDs. This can lead to corrupted touch state or out-of-bounds buffer access.
- CVE-2026-80564Unknown
In the Linux kernel, the gve driver lacks an implementation of adjfine, leading to a NULL pointer dereference when triggered from userspace, e.g., via testptp.
- CVE-2026-80563Unknown
A use-after-free vulnerability was found in the Linux kernel's gpio-sloppy-logic-analyzer driver. The 'trigger' debugfs file lacked proper protection, allowing a write to freed memory during device unbind. The issue was fixed by using debugfs_create_file() instead of debugfs_create_file_unsafe().
- CVE-2026-80543Unknown
In the Linux kernel, the xcrb_msg_to_type6cprb_msgx() and xcrb_msg_to_type6_ep11cprb_msgx() functions for s390/zcrypt copy a user space message into a kernel buffer based on length, but further processing assumes 4-byte alignment. As a result, up to 3 bytes of uninitialized kernel memory are forwarded to further processing, potentially exposing kernel memory to the crypto card firmware.
- CVE-2026-80542Unknown
In the Linux kernel, the amdgpu driver for AMD Display has a NULL pointer dereference in amdgpu_dm_crtc_set_vblank() when vblank is enabled or queried before a stream is attached to acrtc_state->stream. This can lead to a system crash.
- CVE-2026-80535Unknown
In the Linux kernel XFS filesystem, during directory tree repair, a self-referential directory may be detected. In such a case, the repair code attempts to lock the same inode twice (double iolock/ilock), leading to a deadlock. The fix detects this corner case and handles it appropriately.
- CVE-2026-80533Unknown
In the Linux kernel XFS filesystem, during AGI repair, the function xrep_iunlink_walk_ondisk_bucket may attempt to use the pointer sc->sa.agi_bp, which can be null if the buffer verifier fails. The fix uses ragi->agi_bp instead, which skips verifier checks, to avoid walking off the end of memory.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net/sched: dualpi2: fix GSO backlog accounting When DualPI2 splits a GSO skb into N segments, it propagates N additional packets to its parent before returning NET_XMIT_SUCCESS. The parent then accounts for the original skb once more, leaving its qlen one larger than the number of packets actually queued. With QFQ as the parent, after all real packets are dequeued, QFQ still has a non-zero qlen while its in-service aggregate has no active classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes the result to qfq_peek_skb(), causing a NULL pointer dereference. Follow the same pattern used by tbf_segment() and taprio: count only successfully queued segments, propagate the difference between the original skb and those segments, and return NET_XMIT_SUCCESS whenever at least one segment was queued.

