{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90001","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.780Z","datePublished":"2026-09-16T10:33:12.063Z","dateUpdated":"2026-09-16T14:41:17.464Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-16T14:41:17.464Z"},"descriptions":[{"lang":"en","value":"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, 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."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - HID-BPF attach and unreg are reached only through local bpf() syscalls (BPF_MAP_TYPE_STRUCT_OPS / BPF_PROG_TYPE_STRUCT_OPS). Concurrent hid_destroy_device() is also local (uhid UHID_DESTROY/close or HID teardown), not a network or adjacent-radio packet path.\nAC:L - The attacker controls both sides of the TOCTOU race: attach HID-BPF, then concurrently delete the struct_ops map (hid_bpf_unreg) and destroy the HID device (e.g. uhid close). Destroy never took prog_list_lock, so unreg does not block on it and the double-put is reliably hittable.\nPR:L - Loading STRUCT_OPS maps/programs requires CAP_BPF and CAP_PERFMON, which can be delegated via BPF tokens into user namespaces rather than init-namespace root. /dev/uhid is also granted to the seat user on typical desktop systems, so real root is not required.\nUI:N - The attacker creates their own uhid HID device, loads and attaches HID-BPF struct_ops, then races map delete against device destroy in their own processes. No victim action such as plugging in hardware or mounting a filesystem is required.\nS:U - The double-put use-after-free of struct hid_device stays inside the host kernel HID/BPF authority and is a standard local privilege-escalation primitive, not a VM, IOMMU, or sandbox boundary crossing.\nC:H - Double-putting struct hid_device frees it while hid_destroy_device() still uses it. Use-after-free of this large kobject, which holds driver callbacks and pointers, enables an attacker-controlled kernel memory read primitive.\nI:H - The same use-after-free lets the attacker reclaim the freed hid_device via heap spray and corrupt ll_driver/hiddev function pointers or adjacent heap objects, yielding arbitrary kernel writes and control-flow hijacking.\nA:H - Even without full exploitation, dropping the hid_device refcount to zero while hid_remove_device()/put_device() still run causes a kernel oops, panic, or hang on the subsequent use of freed memory."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/bpf/hid_bpf_struct_ops.c"],"versions":[{"version":"ebc0d8093e8c97de459615438edefad1a4ac352c","lessThan":"401359684620145be710de97b87e1a47abfe1459","status":"affected","versionType":"git"},{"version":"ebc0d8093e8c97de459615438edefad1a4ac352c","lessThan":"c7f927aa8b55008ed5ea0814313d5dad771dcf3c","status":"affected","versionType":"git"},{"version":"ebc0d8093e8c97de459615438edefad1a4ac352c","lessThan":"bfb7939788f3c8dd080a4dd81e38d625b35d194e","status":"affected","versionType":"git"},{"version":"ebc0d8093e8c97de459615438edefad1a4ac352c","lessThan":"9cdc7e6dc7a99ad7311ad5e7c145f2b9ce4e24b0","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/bpf/hid_bpf_struct_ops.c"],"versions":[{"version":"6.11","status":"affected"},{"version":"0","lessThan":"6.11","status":"unaffected","versionType":"semver"},{"version":"6.12.110","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.51","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.5","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.12.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.3-rc2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/401359684620145be710de97b87e1a47abfe1459"},{"url":"https://git.kernel.org/stable/c/c7f927aa8b55008ed5ea0814313d5dad771dcf3c"},{"url":"https://git.kernel.org/stable/c/bfb7939788f3c8dd080a4dd81e38d625b35d194e"},{"url":"https://git.kernel.org/stable/c/9cdc7e6dc7a99ad7311ad5e7c145f2b9ce4e24b0"}],"title":"HID: bpf: serialize device reference release in struct_ops destroy path","x_generator":{"engine":"bippy-1.2.0"}}}}