{"api_version":"1","generated_at":"2026-05-28T23:08:20+00:00","cve":"CVE-2026-46123","urls":{"html":"https://cve.report/CVE-2026-46123","api":"https://cve.report/api/cve/CVE-2026-46123.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-46123","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-46123"},"summary":{"title":"Bluetooth: virtio_bt: clamp rx length before skb_put","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: virtio_bt: clamp rx length before skb_put\n\nvirtbt_rx_work() calls skb_put(skb, len) where len comes directly\nfrom virtqueue_get_buf() with no validation against the buffer we\nposted to the device. The RX skb is allocated in virtbt_add_inbuf()\nand exposed to virtio as exactly 1000 bytes via sg_init_one().\n\nChecking len against skb_tailroom(skb) is not sufficient because\nalloc_skb() can leave more tailroom than the 1000 bytes actually\nhanded to the device. A malicious or buggy backend can therefore\nreport used.len between 1001 and skb_tailroom(skb), causing skb_put()\nto include uninitialized kernel heap bytes that were never written by\nthe device.\n\nThe same path also accepts len == 0, in which case skb_put(skb, 0)\nleaves the skb empty but virtbt_rx_handle() still reads the pkt_type\nbyte from skb->data, consuming uninitialized memory.\n\nDefine VIRTBT_RX_BUF_SIZE once and reuse it in alloc_skb() and\nsg_init_one(), and gate virtbt_rx_work() on that same constant so\nthe bound checked matches the buffer actually exposed to the device.\nReject used.len == 0 in the same gate so an empty completion can\nno longer reach virtbt_rx_handle().\n\nUse bt_dev_err_ratelimited() because the length value comes from an\nuntrusted backend that can otherwise flood the kernel log.\n\nSame class of bug as commit c04db81cd028 (\"net/9p: Fix buffer\noverflow in USB transport layer\"), which hardened the USB 9p\ntransport against unchecked device-reported length.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-28 10:16:27","updated_at":"2026-05-28 13:44:01"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/ed41c81d30b211a671667259c3b5feeba0e062d5","name":"https://git.kernel.org/stable/c/ed41c81d30b211a671667259c3b5feeba0e062d5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e6b4296f170d949ebba937cf6a3f247ec9550d2c","name":"https://git.kernel.org/stable/c/e6b4296f170d949ebba937cf6a3f247ec9550d2c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b40cdd1b1370d76e9e760af4490cb4a351cceead","name":"https://git.kernel.org/stable/c/b40cdd1b1370d76e9e760af4490cb4a351cceead","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/21bd244b6de5d2fe1063c23acc93fbdd2b20d112","name":"https://git.kernel.org/stable/c/21bd244b6de5d2fe1063c23acc93fbdd2b20d112","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6c1730099a6fc18b183bd6c1adad3b54adcaeda9","name":"https://git.kernel.org/stable/c/6c1730099a6fc18b183bd6c1adad3b54adcaeda9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-46123","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46123","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be ed41c81d30b211a671667259c3b5feeba0e062d5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be 6c1730099a6fc18b183bd6c1adad3b54adcaeda9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be b40cdd1b1370d76e9e760af4490cb4a351cceead git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be e6b4296f170d949ebba937cf6a3f247ec9550d2c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be 21bd244b6de5d2fe1063c23acc93fbdd2b20d112 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cf2719a21fdb9d4c8e9c834d279163609bef575d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9b67438e315b925a699f0178f4a48baf3d2d6ef4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.15.78 5.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.0.8 6.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.140 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.88 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.30 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.7 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/bluetooth/virtio_bt.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"ed41c81d30b211a671667259c3b5feeba0e062d5","status":"affected","version":"160fbcf3bfb93c3c086427f9f4c8bc70f217e9be","versionType":"git"},{"lessThan":"6c1730099a6fc18b183bd6c1adad3b54adcaeda9","status":"affected","version":"160fbcf3bfb93c3c086427f9f4c8bc70f217e9be","versionType":"git"},{"lessThan":"b40cdd1b1370d76e9e760af4490cb4a351cceead","status":"affected","version":"160fbcf3bfb93c3c086427f9f4c8bc70f217e9be","versionType":"git"},{"lessThan":"e6b4296f170d949ebba937cf6a3f247ec9550d2c","status":"affected","version":"160fbcf3bfb93c3c086427f9f4c8bc70f217e9be","versionType":"git"},{"lessThan":"21bd244b6de5d2fe1063c23acc93fbdd2b20d112","status":"affected","version":"160fbcf3bfb93c3c086427f9f4c8bc70f217e9be","versionType":"git"},{"status":"affected","version":"cf2719a21fdb9d4c8e9c834d279163609bef575d","versionType":"git"},{"status":"affected","version":"9b67438e315b925a699f0178f4a48baf3d2d6ef4","versionType":"git"},{"lessThan":"5.16","status":"affected","version":"5.15.78","versionType":"semver"},{"lessThan":"6.1","status":"affected","version":"6.0.8","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/bluetooth/virtio_bt.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.1"},{"lessThan":"6.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.140","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.88","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.30","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.140","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.88","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.30","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.7","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc3","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.78","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0.8","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: virtio_bt: clamp rx length before skb_put\n\nvirtbt_rx_work() calls skb_put(skb, len) where len comes directly\nfrom virtqueue_get_buf() with no validation against the buffer we\nposted to the device. The RX skb is allocated in virtbt_add_inbuf()\nand exposed to virtio as exactly 1000 bytes via sg_init_one().\n\nChecking len against skb_tailroom(skb) is not sufficient because\nalloc_skb() can leave more tailroom than the 1000 bytes actually\nhanded to the device. A malicious or buggy backend can therefore\nreport used.len between 1001 and skb_tailroom(skb), causing skb_put()\nto include uninitialized kernel heap bytes that were never written by\nthe device.\n\nThe same path also accepts len == 0, in which case skb_put(skb, 0)\nleaves the skb empty but virtbt_rx_handle() still reads the pkt_type\nbyte from skb->data, consuming uninitialized memory.\n\nDefine VIRTBT_RX_BUF_SIZE once and reuse it in alloc_skb() and\nsg_init_one(), and gate virtbt_rx_work() on that same constant so\nthe bound checked matches the buffer actually exposed to the device.\nReject used.len == 0 in the same gate so an empty completion can\nno longer reach virtbt_rx_handle().\n\nUse bt_dev_err_ratelimited() because the length value comes from an\nuntrusted backend that can otherwise flood the kernel log.\n\nSame class of bug as commit c04db81cd028 (\"net/9p: Fix buffer\noverflow in USB transport layer\"), which hardened the USB 9p\ntransport against unchecked device-reported length."}],"providerMetadata":{"dateUpdated":"2026-05-28T09:35:38.003Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/ed41c81d30b211a671667259c3b5feeba0e062d5"},{"url":"https://git.kernel.org/stable/c/6c1730099a6fc18b183bd6c1adad3b54adcaeda9"},{"url":"https://git.kernel.org/stable/c/b40cdd1b1370d76e9e760af4490cb4a351cceead"},{"url":"https://git.kernel.org/stable/c/e6b4296f170d949ebba937cf6a3f247ec9550d2c"},{"url":"https://git.kernel.org/stable/c/21bd244b6de5d2fe1063c23acc93fbdd2b20d112"}],"title":"Bluetooth: virtio_bt: clamp rx length before skb_put","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-46123","datePublished":"2026-05-28T09:35:38.003Z","dateReserved":"2026-05-13T15:03:33.098Z","dateUpdated":"2026-05-28T09:35:38.003Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-28 10:16:27","lastModifiedDate":"2026-05-28 13:44:01","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"46123","Ordinal":"1","Title":"Bluetooth: virtio_bt: clamp rx length before skb_put","CVE":"CVE-2026-46123","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"46123","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: virtio_bt: clamp rx length before skb_put\n\nvirtbt_rx_work() calls skb_put(skb, len) where len comes directly\nfrom virtqueue_get_buf() with no validation against the buffer we\nposted to the device. The RX skb is allocated in virtbt_add_inbuf()\nand exposed to virtio as exactly 1000 bytes via sg_init_one().\n\nChecking len against skb_tailroom(skb) is not sufficient because\nalloc_skb() can leave more tailroom than the 1000 bytes actually\nhanded to the device. A malicious or buggy backend can therefore\nreport used.len between 1001 and skb_tailroom(skb), causing skb_put()\nto include uninitialized kernel heap bytes that were never written by\nthe device.\n\nThe same path also accepts len == 0, in which case skb_put(skb, 0)\nleaves the skb empty but virtbt_rx_handle() still reads the pkt_type\nbyte from skb->data, consuming uninitialized memory.\n\nDefine VIRTBT_RX_BUF_SIZE once and reuse it in alloc_skb() and\nsg_init_one(), and gate virtbt_rx_work() on that same constant so\nthe bound checked matches the buffer actually exposed to the device.\nReject used.len == 0 in the same gate so an empty completion can\nno longer reach virtbt_rx_handle().\n\nUse bt_dev_err_ratelimited() because the length value comes from an\nuntrusted backend that can otherwise flood the kernel log.\n\nSame class of bug as commit c04db81cd028 (\"net/9p: Fix buffer\noverflow in USB transport layer\"), which hardened the USB 9p\ntransport against unchecked device-reported length.","Type":"Description","Title":"Bluetooth: virtio_bt: clamp rx length before skb_put"}]}}}