{"id":"CVE-2026-46320","state":"PUBLISHED","title":"tap: free page on error paths in tap_get_user_xdp()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntap: free page on error paths in tap_get_user_xdp()\n\ntap_get_user_xdp() rejects a frame shorter than ETH_HLEN with -EINVAL,\nand returns -ENOMEM when build_skb() fails. Both paths jump to the err\nlabel without freeing the page that vhost_net_build_xdp() allocated for\nthe frame. tap_sendmsg() discards the per-buffer return value and always\nreturns 0, so vhost_tx_batch() takes the success path and never frees\nthe page; each rejected frame in a batch leaks one page-frag chunk.\n\nFree the page on both error paths, before the skb is built. This is the\ntap counterpart of the same leak in tun_xdp_one().","publishedAt":"2026-06-09T12:11:12.882Z","updatedAt":"2026-10-19T19:36:58.167Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"8d03e65eb6cfbffec471a6b65416f93679bf3286","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"f979971835dddbca86cf99e3b2e2b94a408a1ab2","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"3f52a86a482a69294c50a5a2a097bd6f4104990a","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"d30aac0fa00ca0afc3e08174cf7f974a66bdcf05","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"d68eab61944a9b0826fa2e954e42db1aa3201b7a","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"e27c17346628cb56843a83f93ac63c314c00f388","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"18a84c35842e19cd3c5534d8cee73d31863f696d","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/tap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/tap.c"]}],"references":["https://git.kernel.org/stable/c/8d03e65eb6cfbffec471a6b65416f93679bf3286","https://git.kernel.org/stable/c/f979971835dddbca86cf99e3b2e2b94a408a1ab2","https://git.kernel.org/stable/c/3f52a86a482a69294c50a5a2a097bd6f4104990a","https://git.kernel.org/stable/c/d30aac0fa00ca0afc3e08174cf7f974a66bdcf05","https://git.kernel.org/stable/c/d68eab61944a9b0826fa2e954e42db1aa3201b7a","https://git.kernel.org/stable/c/e27c17346628cb56843a83f93ac63c314c00f388","https://git.kernel.org/stable/c/18a84c35842e19cd3c5534d8cee73d31863f696d","https://git.kernel.org/stable/c/3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":["CWE-401"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46320.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46320","state":"PUBLISHED","datePublished":"2026-06-09T12:11:12.882Z","dateUpdated":"2026-10-19T19:36:58.167Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.112Z"},"containers":{"cna":{"title":"tap: free page on error paths in tap_get_user_xdp()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntap: free page on error paths in tap_get_user_xdp()\n\ntap_get_user_xdp() rejects a frame shorter than ETH_HLEN with -EINVAL,\nand returns -ENOMEM when build_skb() fails. Both paths jump to the err\nlabel without freeing the page that vhost_net_build_xdp() allocated for\nthe frame. tap_sendmsg() discards the per-buffer return value and always\nreturns 0, so vhost_tx_batch() takes the success path and never frees\nthe page; each rejected frame in a batch leaks one page-frag chunk.\n\nFree the page on both error paths, before the skb is built. This is the\ntap counterpart of the same leak in tun_xdp_one()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"8d03e65eb6cfbffec471a6b65416f93679bf3286","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"f979971835dddbca86cf99e3b2e2b94a408a1ab2","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"3f52a86a482a69294c50a5a2a097bd6f4104990a","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"d30aac0fa00ca0afc3e08174cf7f974a66bdcf05","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"d68eab61944a9b0826fa2e954e42db1aa3201b7a","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"e27c17346628cb56843a83f93ac63c314c00f388","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"18a84c35842e19cd3c5534d8cee73d31863f696d","versionType":"git"},{"version":"0efac27791ee068075d80f07c55a229b1335ce12","status":"affected","lessThan":"3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/tap.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/tap.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8d03e65eb6cfbffec471a6b65416f93679bf3286"},{"url":"https://git.kernel.org/stable/c/f979971835dddbca86cf99e3b2e2b94a408a1ab2"},{"url":"https://git.kernel.org/stable/c/3f52a86a482a69294c50a5a2a097bd6f4104990a"},{"url":"https://git.kernel.org/stable/c/d30aac0fa00ca0afc3e08174cf7f974a66bdcf05"},{"url":"https://git.kernel.org/stable/c/d68eab61944a9b0826fa2e954e42db1aa3201b7a"},{"url":"https://git.kernel.org/stable/c/e27c17346628cb56843a83f93ac63c314c00f388"},{"url":"https://git.kernel.org/stable/c/18a84c35842e19cd3c5534d8cee73d31863f696d"},{"url":"https://git.kernel.org/stable/c/3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","baseScore":7.4,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - The bug is reached when guest-originated TX data crosses the virtio/vhost-net/macvtap boundary into the host tap driver; this is the same adjacent virtual-network path as CVE-2024-41090, not a remote Internet packet to the host stack.\nAC:L - An attacker controls the virtio TX virtqueue and can reliably submit frames shorter than ETH_HLEN or force build_skb failures; each batch can leak up to 64 page-frags and be repeated in a tight loop without race conditions.\nPR:N - In the highest-impact cloud-KVM scenario, a malicious VM tenant needs no host credentials or capabilities—only the ability to send packets from inside an already-provisioned guest using virtio-net.\nUI:N - Exploitation requires no action from the host administrator or any other user beyond normal VM operation; the guest attacker drives the virtqueue directly.\nS:C - The leak occurs in the host kernel while processing guest-supplied descriptors, crossing the VM/host security boundary and degrading host-wide availability beyond the guest’s own security scope.\nC:N - This is a missing put_page on error paths causing page-frag retention; there is no out-of-bounds read, use-after-free, or other memory corruption that could disclose kernel data.\nI:N - No memory is corrupted or written beyond the leaked page allocation; the bug cannot be leveraged for arbitrary write, code execution, or integrity compromise.\nA:H - Sustained submission of short or failing frames leaks one page-frag per rejected buffer; at scale this exhausts host memory and can trigger OOM kills or host panic, matching the identical tun-side fix analysis."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:31:15.165Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.12.94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:21:34.364Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-46320","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:22:00.850427Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-401","lang":"en","type":"CWE","description":"CWE-401 Missing Release of Memory after Effective Lifetime"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:36:58.167Z"}}]}}}