Linux kernel bsg: sense data copy ignores max_response_len and overruns the user buffer

Impact

Completion of an io_uring-submitted SCSI generic command copied scmd->sense_len bytes into the caller's response buffer without honouring max_response_len, so a caller that supplied a buffer smaller than the real sense length (up to SCSI_SENSE_BUFFERSIZE) had memory past the buffer overwritten. NVD rates it 7.8 local with high confidentiality, integrity and availability impact, consistent with local privilege escalation. On a GPU node this matters where /dev/bsg or SG passthrough is exposed to a workload or a storage management container - direct disk passthrough setups are the realistic path. A node that hits this needs draining before it can take the fixed kernel.

Who can reach it

Local user with access to a SCSI bsg device node and the ability to submit io_uring passthrough commands. Authentication as a local user is required; no remote path.

What to do

Take the stable kernel containing commits 5d326efc334e / ece06de72673, then drain and reboot each affected node - kernel fixes are not hot-patchable here. Until then, restrict access to /dev/bsg* so unprivileged tenants and containers cannot reach SCSI passthrough.

References

Related entries

• Linux kernel page allocator: unsafe spin_trylock in NMI context on uniprocessor buildsCVE-2026-90046 · Linux kernel mm/page_alloc (free_pages_nolock in NMI on UP builds)High
• Linux kernel acomp: stack-request clone is undersized, letting async offload drivers write past the slab objectCVE-2026-90069 · Linux kernel crypto acomp (ACOMP_REQUEST_ON_STACK request cloning)High
• Linux kernel XDP: BPF_LINK_UPDATE bypasses offload checks, putting a device-bound program on the software pathCVE-2026-90146 · Linux kernel bpf/xdp (bpf_xdp_link_update offload checks)High
• Linux kernel BPF verifier (atomic RMW destination pointer type tracking): The verifier recorded an instruction'sCVE-2026-90177 · Linux kernel BPF verifier (atomic RMW destination pointer type tracking)High
• Linux kernel BPF: use-after-free when multi-attach trampoline update fails and the still-live old image is freedCVE-2026-90210 · Linux kernel BPF trampoline (bpf_trampoline_multi_attach_free on update failure)High
• Linux kernel BPF verifier: iterator stack slots compared without pointer type, pruning an unsafe pathCVE-2026-90217 · Linux kernel BPF verifier (STACK_ITER slot type comparison during state pruning)High