{"id":"CVE-2026-90001","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: bpf: serialize device reference release in struct_ops destroy path\n\n__hid_bpf_ops_destroy_device() and hid_bpf_unreg() can race on the\nsame registration reference,…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: bpf: serialize device reference release in struct_ops destroy path\n\n__hid_bpf_ops_destroy_device() and hid_bpf_unreg() can race on the\nsame registration reference,…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= ebc0d8093e8c97de459615438edefad1a4ac352c < 401359684620145be710de97b87e1a47abfe1459","Linux >= ebc0d8093e8c97de459615438edefad1a4ac352c < c7f927aa8b55008ed5ea0814313d5dad771dcf3c","Linux >= ebc0d8093e8c97de459615438edefad1a4ac352c < bfb7939788f3c8dd080a4dd81e38d625b35d194e","Linux >= ebc0d8093e8c97de459615438edefad1a4ac352c < 9cdc7e6dc7a99ad7311ad5e7c145f2b9ce4e24b0","Linux 6.11"],"published":"2026-09-16","updated":"2026-09-16","sourceUpdated":"2026-09-16T15:18:23.880","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90001","references":[{"url":"https://git.kernel.org/stable/c/401359684620145be710de97b87e1a47abfe1459","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9cdc7e6dc7a99ad7311ad5e7c145f2b9ce4e24b0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bfb7939788f3c8dd080a4dd81e38d625b35d194e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c7f927aa8b55008ed5ea0814313d5dad771dcf3c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-16T10:53:53.946Z","epss":0.00163,"epssPercentile":0.05964,"slug":"CVE-2026-90001","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nHID: bpf: serialize device reference release in struct_ops destroy path\n\n__hid_bpf_ops_destroy_device() and hid_bpf_unreg() can race on the\nsame registration reference, double-putting struct hid_device and\nfreeing it while hid_destroy_device() still uses it.  Serialize the\nremove/NULL decision under hdev->bpf.prog_list_lock so exactly one\npath releases each registration reference: unreg re-checks ops->hdev\nunder the lock and returns without putting when the destroy path\nalready cleared it; all put_device() calls happen after the lock is\ndropped, which is safe because a concurrent unreg then observes\nops->hdev == NULL under the lock.\n\nBackground: each successful attach (hid_bpf_ops_reg) acquires one\ndevice reference (hid_get_device()).  Two paths can release it:\n\n- device destruction: hid_destroy_device() -> hid_bpf_destroy_device()\n  -> __hid_bpf_ops_destroy_device(), which walks hdev->bpf.prog_list\n  under rcu_read_lock() and drops one reference per attached program;\n- BPF link release: bpf map delete (no BPF_F_LINK) synchronously calls\n  st_ops->unreg() -> hid_bpf_unreg(), which drops the reference for\n  its own registration.\n\nThe coordination handshake (e->hdev = NULL on the destroy side vs\n\"if (!hdev) return\" on the unreg side) is a TOCTOU check: the two\npaths run under different lock domains (rcu_read_lock vs\nprog_list_lock), so a concurrent unreg can read ops->hdev as\nnon-NULL, block on prog_list_lock, and then proceed while the\ndestroy traversal executes - both paths then drop the same\nreference.  The refcount reaches zero legitimately (each decrement\nis individually valid), so no refcount_t saturation fires: the\ndevice is simply freed while the transport is still inside\nhid_destroy_device(), and subsequent teardown touches freed memory.\n\nThe fix serializes the remove/NULL decision under prog_list_lock on\nboth sides and moves the destroy-side puts outside the lock.  With\nthe lock held, plain reads/writes of ops->hdev are sufficient; no\nREAD_ONCE/WRITE_ONCE are added, keeping the patch minimal.\n\nUnlocked-read safety: the unlocked read of ops->hdev at the top of\nhid_bpf_unreg() cannot touch a freed device, because the unreg path\nitself still holds this registration's reference (released only by\nits own hid_put_device() after the lock is dropped), and a destroy\ntraversal that already cleared ops->hdev makes the lock-internal\nre-check return early without any put.  At most one of the two\npaths releases each registration reference.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205037,"id":"CVE-2026-90001","ts":1789570704887,"field":"cvss","old":null,"new":"7.8"},{"seq":205036,"id":"CVE-2026-90001","ts":1789570704887,"field":"severity","old":"none","new":"high"}]}