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VulnerabilityPublished Updated

CVE-2026-90312: Linux kernel · bpf: Check load-acquire src ptr type before the load

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.8 High.

Data as of 28 Oct 2026, 01:13 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 17 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-5.5 – 7.0.0-38.38
23 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1003.3 – 7.0.0-1017.17
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1016.16
9 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
13 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1002.3 – 7.0.0-1008.9
6 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Check load-acquire src ptr type before the load check_atomic_load() calls check_load_mem() before atomic_ptr_type_ok(). For a load-acquire that fetches into its own source register (dst_reg == src_reg), check_load_mem() overwrites src_reg's type with the type of the loaded value, so the subsequent atomic_ptr_type_ok() no longer sees the source pointer and fails to reject the disallowed types (ctx, pkt, flow_keys, sock). Since bpf_convert_ctx_accesses() does not rewrite atomic loads, the raw access to the underlying kernel object is left in place. The destination type is taken from the ctx access itself, so a load-acquire of the sk field of struct __sk_buff for example leaves the register typed as PTR_TO_SOCK_COMMON_OR_NULL, which type_is_sk_pointer() does not match either, while it actually holds unconverted struct sk_buff bytes. Once the NULL check has passed this is a type confusion, not just a leak of kernel data. Validate src_reg with check_reg_arg() and check the source pointer type with atomic_ptr_type_ok() before the load again, mirroring check_atomic_rmw(). Out-of-range register numbers are already rejected earlier by check_and_resolve_insns() (commit 503d21ef8eac ("bpf: Do register range validation early")), and the only exemption there, is_stack_arg_ldx(), requires BPF_LDX | BPF_MEM | BPF_DW and thus never matches a BPF_ATOMIC insn. atomic_ptr_type_ok() can therefore not dereference register state out of bounds, that is, the out-of-bounds read addressed by the Fixes commit below does not reappear (as proven also via selftest).

References

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