{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23294 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23294 is a high-severity vulnerability in Linux kernel, published on 25 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-23294 and fix it if it is affected.\n\nWhat it is: CVE-2026-23294 is a high-severity vulnerability in Linux kernel, published on 25 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-23294 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-23294/ (Markdown: https://insights.sbomify.com/CVE-2026-23294/index.md)","id":"CVE-2026-23294","markdown":"https://insights.sbomify.com/CVE-2026-23294/index.md","name":"CVE-2026-23294","record":{"aliases":["BELL-CVE-2026-23294","DEBIAN-CVE-2026-23294","GHSA-4h26-3w83-pfh6","UBUNTU-CVE-2026-23294"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A race condition in the Linux kernel's BPF devmap on PREEMPT_RT systems allows concurrent access leading to use-after-free and potential code execution.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix race in devmap on PREEMPT_RT\n\nOn PREEMPT_RT kernels, the per-CPU xdp_dev_bulk_queue (bq) can be\naccessed concurrently by multiple preemptible tasks on the same CPU.\n\nThe original code assumes bq_enqueue() and __dev_flush() run atomically\nwith respect to each other on the same CPU, relying on\nlocal_bh_disable() to prevent preemption. However, on PREEMPT_RT,\nlocal_bh_disable() only calls migrate_disable() (when\nPREEMPT_RT_NEEDS_BH_LOCK is not set) and does not disable\npreemption, which allows CFS scheduling to preempt a task during\nbq_xmit_all(), enabling another task on the same CPU to enter\nbq_enqueue() and operate on the same per-CPU bq concurrently.\n\nThis leads to several races:\n\n1. Double-free / use-after-free on bq-\u003eq[]: bq_xmit_all() snapshots\n   cnt = bq-\u003ecount, then iterates bq-\u003eq[0..cnt-1] to transmit frames.\n   If preempted after the snapshot, a second task can call bq_enqueue()\n   -\u003e bq_xmit_all() on the same bq, transmitting (and freeing) the\n   same frames. When the first task resumes, it operates on stale\n   pointers in bq-\u003eq[], causing use-after-free.\n\n2. bq-\u003ecount and bq-\u003eq[] corruption: concurrent bq_enqueue() modifying\n   bq-\u003ecount and bq-\u003eq[] while bq_xmit_all() is reading them.\n\n3. dev_rx/xdp_prog teardown race: __dev_flush() clears bq-\u003edev_rx and\n   bq-\u003exdp_prog after bq_xmit_all(). If preempted between\n   bq_xmit_all() return and bq-\u003edev_rx = NULL, a preempting\n   bq_enqueue() sees dev_rx still set (non-NULL), skips adding bq to\n   the flush_list, and enqueues a frame. When __dev_flush() resumes,\n   it clears dev_rx and removes bq from the flush_list, orphaning the\n   newly enqueued frame.\n\n4. __list_del_clearprev() on flush_node: similar to the cpumap race,\n   both tasks can call __list_del_clearprev() on the same flush_node,\n   the second dereferences the prev pointer already set to NULL.\n\nThe race between task A (__dev_flush -\u003e bq_xmit_all) and task B\n(bq_enqueue -\u003e bq_xmit_all) on the same CPU:\n\n  Task A (xdp_do_flush)          Task B (ndo_xdp_xmit redirect)\n  ----------------------         --------------------------------\n  __dev_flush(flush_list)\n    bq_xmit_all(bq)\n      cnt = bq-\u003ecount  /* e.g. 16 */\n      /* start iterating bq-\u003eq[] */\n    \u003c-- CFS preempts Task A --\u003e\n                                   bq_enqueue(dev, xdpf)\n                                     bq-\u003ecount == DEV_MAP_BULK_SIZE\n                                     bq_xmit_all(bq, 0)\n                                       cnt = bq-\u003ecount  /* same 16! */\n                                       ndo_xdp_xmit(bq-\u003eq[])\n                                       /* frames freed by driver */\n                                       bq-\u003ecount = 0\n    \u003c-- Task A resumes --\u003e\n      ndo_xdp_xmit(bq-\u003eq[])\n      /* use-after-free: frames already freed! */\n\nFix this by adding a local_lock_t to xdp_dev_bulk_queue and acquiring\nit in bq_enqueue() and __dev_flush(). These paths already run under\nlocal_bh_disable(), so use local_lock_nested_bh() which on non-RT is\na pure annotation with no overhead, and on PREEMPT_RT provides a\nper-CPU sleeping lock that serializes access to the bq.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"bpf: Fix race in devmap on PREEMPT_RT","id":"CVE-2026-23294","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"accel/amdxdna: Fix dead lock for suspend and resume","id":"CVE-2026-23295"},"packages":[],"prev":{"headline":"net: vxlan: fix nd_tbl NULL dereference when IPv6 is disabled","id":"CVE-2026-23293"},"products":["Linux"],"published":"2026-03-25","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-05","vendors":["Linux"]},"summary":"A race condition in the Linux kernel's BPF devmap on PREEMPT_RT systems allows concurrent access leading to use-after-free and potential code execution.","url":"https://insights.sbomify.com/CVE-2026-23294/"}