{"api_version":"1","generated_at":"2026-04-25T00:49:06+00:00","cve":"CVE-2026-31607","urls":{"html":"https://cve.report/CVE-2026-31607","api":"https://cve.report/api/cve/CVE-2026-31607.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31607","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31607"},"summary":{"title":"usbip: validate number_of_packets in usbip_pack_ret_submit()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: validate number_of_packets in usbip_pack_ret_submit()\n\nWhen a USB/IP client receives a RET_SUBMIT response,\nusbip_pack_ret_submit() unconditionally overwrites\nurb->number_of_packets from the network PDU. This value is\nsubsequently used as the loop bound in usbip_recv_iso() and\nusbip_pad_iso() to iterate over urb->iso_frame_desc[], a flexible\narray whose size was fixed at URB allocation time based on the\n*original* number_of_packets from the CMD_SUBMIT.\n\nA malicious USB/IP server can set number_of_packets in the response\nto a value larger than what was originally submitted, causing a heap\nout-of-bounds write when usbip_recv_iso() writes to\nurb->iso_frame_desc[i] beyond the allocated region.\n\nKASAN confirmed this with kernel 7.0.0-rc5:\n\n  BUG: KASAN: slab-out-of-bounds in usbip_recv_iso+0x46a/0x640\n  Write of size 4 at addr ffff888106351d40 by task vhci_rx/69\n\n  The buggy address is located 0 bytes to the right of\n   allocated 320-byte region [ffff888106351c00, ffff888106351d40)\n\nThe server side (stub_rx.c) and gadget side (vudc_rx.c) already\nvalidate number_of_packets in the CMD_SUBMIT path since commits\nc6688ef9f297 (\"usbip: fix stub_rx: harden CMD_SUBMIT path to handle\nmalicious input\") and b78d830f0049 (\"usbip: fix vudc_rx: harden\nCMD_SUBMIT path to handle malicious input\"). The server side validates\nagainst USBIP_MAX_ISO_PACKETS because no URB exists yet at that point.\nOn the client side we have the original URB, so we can use the tighter\nbound: the response must not exceed the original number_of_packets.\n\nThis mirrors the existing validation of actual_length against\ntransfer_buffer_length in usbip_recv_xbuff(), which checks the\nresponse value against the original allocation size.\n\nKelvin Mbogo's series (\"usb: usbip: fix integer overflow in\nusbip_recv_iso()\", v2) hardens the receive-side functions themselves;\nthis patch complements that work by catching the bad value at its\nsource -- in usbip_pack_ret_submit() before the overwrite -- and\nusing the tighter per-URB allocation bound rather than the global\nUSBIP_MAX_ISO_PACKETS limit.\n\nFix this by checking rpdu->number_of_packets against\nurb->number_of_packets in usbip_pack_ret_submit() before the\noverwrite. On violation, clamp to zero so that usbip_recv_iso() and\nusbip_pad_iso() safely return early.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-24 15:16:39","updated_at":"2026-04-24 17:51:40"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/ef8ebb1c637b4cfb61a9dd2e013376774ee2033b","name":"https://git.kernel.org/stable/c/ef8ebb1c637b4cfb61a9dd2e013376774ee2033b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8d155e2d1c4102f74f82a2bf9c016164bb0f7384","name":"https://git.kernel.org/stable/c/8d155e2d1c4102f74f82a2bf9c016164bb0f7384","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5e1c4ece08ccdc197177631f111845a2c68eede3","name":"https://git.kernel.org/stable/c/5e1c4ece08ccdc197177631f111845a2c68eede3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/906f16a836de13fe61f49cdce2f66f2dbd14caf4","name":"https://git.kernel.org/stable/c/906f16a836de13fe61f49cdce2f66f2dbd14caf4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31607","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31607","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 8d155e2d1c4102f74f82a2bf9c016164bb0f7384 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 906f16a836de13fe61f49cdce2f66f2dbd14caf4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ef8ebb1c637b4cfb61a9dd2e013376774ee2033b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 5e1c4ece08ccdc197177631f111845a2c68eede3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.83 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.24 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.14 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.1 7.0.* semver","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/usb/usbip/usbip_common.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"8d155e2d1c4102f74f82a2bf9c016164bb0f7384","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"906f16a836de13fe61f49cdce2f66f2dbd14caf4","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"ef8ebb1c637b4cfb61a9dd2e013376774ee2033b","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"5e1c4ece08ccdc197177631f111845a2c68eede3","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/usb/usbip/usbip_common.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.83","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.24","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.14","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.1","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.83","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.24","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: validate number_of_packets in usbip_pack_ret_submit()\n\nWhen a USB/IP client receives a RET_SUBMIT response,\nusbip_pack_ret_submit() unconditionally overwrites\nurb->number_of_packets from the network PDU. This value is\nsubsequently used as the loop bound in usbip_recv_iso() and\nusbip_pad_iso() to iterate over urb->iso_frame_desc[], a flexible\narray whose size was fixed at URB allocation time based on the\n*original* number_of_packets from the CMD_SUBMIT.\n\nA malicious USB/IP server can set number_of_packets in the response\nto a value larger than what was originally submitted, causing a heap\nout-of-bounds write when usbip_recv_iso() writes to\nurb->iso_frame_desc[i] beyond the allocated region.\n\nKASAN confirmed this with kernel 7.0.0-rc5:\n\n  BUG: KASAN: slab-out-of-bounds in usbip_recv_iso+0x46a/0x640\n  Write of size 4 at addr ffff888106351d40 by task vhci_rx/69\n\n  The buggy address is located 0 bytes to the right of\n   allocated 320-byte region [ffff888106351c00, ffff888106351d40)\n\nThe server side (stub_rx.c) and gadget side (vudc_rx.c) already\nvalidate number_of_packets in the CMD_SUBMIT path since commits\nc6688ef9f297 (\"usbip: fix stub_rx: harden CMD_SUBMIT path to handle\nmalicious input\") and b78d830f0049 (\"usbip: fix vudc_rx: harden\nCMD_SUBMIT path to handle malicious input\"). The server side validates\nagainst USBIP_MAX_ISO_PACKETS because no URB exists yet at that point.\nOn the client side we have the original URB, so we can use the tighter\nbound: the response must not exceed the original number_of_packets.\n\nThis mirrors the existing validation of actual_length against\ntransfer_buffer_length in usbip_recv_xbuff(), which checks the\nresponse value against the original allocation size.\n\nKelvin Mbogo's series (\"usb: usbip: fix integer overflow in\nusbip_recv_iso()\", v2) hardens the receive-side functions themselves;\nthis patch complements that work by catching the bad value at its\nsource -- in usbip_pack_ret_submit() before the overwrite -- and\nusing the tighter per-URB allocation bound rather than the global\nUSBIP_MAX_ISO_PACKETS limit.\n\nFix this by checking rpdu->number_of_packets against\nurb->number_of_packets in usbip_pack_ret_submit() before the\noverwrite. On violation, clamp to zero so that usbip_recv_iso() and\nusbip_pad_iso() safely return early."}],"providerMetadata":{"dateUpdated":"2026-04-24T14:42:29.468Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/8d155e2d1c4102f74f82a2bf9c016164bb0f7384"},{"url":"https://git.kernel.org/stable/c/906f16a836de13fe61f49cdce2f66f2dbd14caf4"},{"url":"https://git.kernel.org/stable/c/ef8ebb1c637b4cfb61a9dd2e013376774ee2033b"},{"url":"https://git.kernel.org/stable/c/5e1c4ece08ccdc197177631f111845a2c68eede3"}],"title":"usbip: validate number_of_packets in usbip_pack_ret_submit()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31607","datePublished":"2026-04-24T14:42:29.468Z","dateReserved":"2026-03-09T15:48:24.122Z","dateUpdated":"2026-04-24T14:42:29.468Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-24 15:16:39","lastModifiedDate":"2026-04-24 17:51:40","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31607","Ordinal":"1","Title":"usbip: validate number_of_packets in usbip_pack_ret_submit()","CVE":"CVE-2026-31607","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31607","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: validate number_of_packets in usbip_pack_ret_submit()\n\nWhen a USB/IP client receives a RET_SUBMIT response,\nusbip_pack_ret_submit() unconditionally overwrites\nurb->number_of_packets from the network PDU. This value is\nsubsequently used as the loop bound in usbip_recv_iso() and\nusbip_pad_iso() to iterate over urb->iso_frame_desc[], a flexible\narray whose size was fixed at URB allocation time based on the\n*original* number_of_packets from the CMD_SUBMIT.\n\nA malicious USB/IP server can set number_of_packets in the response\nto a value larger than what was originally submitted, causing a heap\nout-of-bounds write when usbip_recv_iso() writes to\nurb->iso_frame_desc[i] beyond the allocated region.\n\nKASAN confirmed this with kernel 7.0.0-rc5:\n\n  BUG: KASAN: slab-out-of-bounds in usbip_recv_iso+0x46a/0x640\n  Write of size 4 at addr ffff888106351d40 by task vhci_rx/69\n\n  The buggy address is located 0 bytes to the right of\n   allocated 320-byte region [ffff888106351c00, ffff888106351d40)\n\nThe server side (stub_rx.c) and gadget side (vudc_rx.c) already\nvalidate number_of_packets in the CMD_SUBMIT path since commits\nc6688ef9f297 (\"usbip: fix stub_rx: harden CMD_SUBMIT path to handle\nmalicious input\") and b78d830f0049 (\"usbip: fix vudc_rx: harden\nCMD_SUBMIT path to handle malicious input\"). The server side validates\nagainst USBIP_MAX_ISO_PACKETS because no URB exists yet at that point.\nOn the client side we have the original URB, so we can use the tighter\nbound: the response must not exceed the original number_of_packets.\n\nThis mirrors the existing validation of actual_length against\ntransfer_buffer_length in usbip_recv_xbuff(), which checks the\nresponse value against the original allocation size.\n\nKelvin Mbogo's series (\"usb: usbip: fix integer overflow in\nusbip_recv_iso()\", v2) hardens the receive-side functions themselves;\nthis patch complements that work by catching the bad value at its\nsource -- in usbip_pack_ret_submit() before the overwrite -- and\nusing the tighter per-URB allocation bound rather than the global\nUSBIP_MAX_ISO_PACKETS limit.\n\nFix this by checking rpdu->number_of_packets against\nurb->number_of_packets in usbip_pack_ret_submit() before the\noverwrite. On violation, clamp to zero so that usbip_recv_iso() and\nusbip_pad_iso() safely return early.","Type":"Description","Title":"usbip: validate number_of_packets in usbip_pack_ret_submit()"}]}}}