{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38718","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T04:51:24.033Z","datePublished":"2025-09-04T15:33:12.448Z","dateUpdated":"2026-08-05T12:04:15.979Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:04:15.979Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: linearize cloned gso packets in sctp_rcv\n\nA cloned head skb still shares these frag skbs in fraglist with the\noriginal head skb. It's not safe to access these frag skbs.\n\nsyzbot reported two use-of-uninitialized-memory bugs caused by this:\n\n  BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211\n   sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211\n   sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998\n   sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88\n   sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331\n   sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122\n   __release_sock+0x1da/0x330 net/core/sock.c:3106\n   release_sock+0x6b/0x250 net/core/sock.c:3660\n   sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360\n   sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885\n   sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031\n   inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851\n   sock_sendmsg_nosec net/socket.c:718 [inline]\n\nand\n\n  BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987\n   sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987\n   sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88\n   sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331\n   sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148\n   __release_sock+0x1d3/0x330 net/core/sock.c:3213\n   release_sock+0x6b/0x270 net/core/sock.c:3767\n   sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367\n   sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886\n   sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032\n   inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851\n   sock_sendmsg_nosec net/socket.c:712 [inline]\n\nThis patch fixes it by linearizing cloned gso packets in sctp_rcv()."}],"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 - The vulnerable branch requires `skb_is_gso_sctp()`, and `SKB_GSO_SCTP` is set only by the local transmit path (`sk->sk_gso_type` in net/sctp/socket.c:5042, applied in `sctp_packet_pack()`); net/sctp/offload.c registers no GRO handler and virtio/tun cannot carry an SCTP GSO type, so packets arriving from a real network are never `is_gso` and the attacker must originate the packet locally via `sendmsg()` on an SCTP socket looped back over `lo`/`veth`.\nAC:L - The attacker supplies every precondition: an SCTP socket sending more than PMTU to 127.0.0.1 to force the GSO cover-letter skb, and an AF_PACKET or raw socket to guarantee the clone via `dev_queue_xmit_nit()`, all repeatable in a loop; syzbot reproduced it independently twice.\nPR:L - No `capable()` check exists anywhere on the `sendmsg` → `sctp_packet_pack` → `sctp_rcv` → `sctp_inq_pop` path, the SCTP module autoloads on an unprivileged `socket(AF_INET, SOCK_SEQPACKET, IPPROTO_SCTP)`, and the CAP_NET_RAW needed for the cloning tap is obtainable by any local user with `unshare -Urn`.\nUI:N - The attacker performs the send, the clone setup, and the receive entirely from its own processes; no victim action or cooperation is involved.\nS:U - The out-of-bounds accesses and skb metadata corruption occur in kernel heap memory within the same kernel security authority, with no VM, IOMMU, or sandbox boundary crossed.\nC:H - `sctp_inq_pop()` reads chunk headers past the frag skb's valid data (KMSAN uninit-value at inqueue.c:211), and the resulting attacker-influenced `chunk_end`/`datalen` drives `skb_trim()` in `sctp_ulpevent_make_rcvmsg()` on the clone queued for `recvmsg()`, while the co-owner of the shared frags (AF_PACKET/raw socket) reads them at pointers SCTP already advanced — both paths copy adjacent kernel heap out to userspace.\nI:H - SCTP mutates `data`, `len`, and `cb` of frag skbs concurrently owned by another subsystem, and `skb_pull(chunk->skb, sizeof(*ch))` on an already-consumed frag underflows `skb->len` to ~4 GB unchecked, leaving a corrupted length on a live skb while the full SCTP state machine executes on out-of-bounds bytes.\nA:H - The condition is a KASAN/KMSAN-reportable memory-safety violation whose ~4 GB `skb->len` underflow and out-of-range `skb_trim()` produce oops/panic in downstream copy and accounting paths, and any unprivileged local user can retrigger it in a loop."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/input.c"],"versions":[{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"d0194e391bb493aa6cec56d177b14df6b29188d5","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"03d0cc6889e02420125510b5444b570f4bbf53d5","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"cd0e92bb2b7542fb96397ffac639b4f5b099d0cb","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"4506bcaabe004d07be8ff09116a3024fbd6aa965","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"ea094f38d387d1b0ded5dee4a3e5720aa4ce0139","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"7d757f17bc2ef2727994ffa6d5d6e4bc4789a770","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"fc66772607101bd2030a4332b3bd0ea3b3605250","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"1bd5214ea681584c5886fea3ba03e49f93a43c0e","status":"affected","versionType":"git"},{"version":"90017accff61ae89283ad9a51f9ac46ca01633fb","lessThan":"fd60d8a086191fe33c2d719732d2482052fa6805","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/input.c"],"versions":[{"version":"4.8","status":"affected"},{"version":"0","lessThan":"4.8","status":"unaffected","versionType":"semver"},{"version":"5.4.297","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.241","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.190","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.162","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.103","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.43","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.15.11","lessThanOrEqual":"6.15.*","status":"unaffected","versionType":"semver"},{"version":"6.16.2","lessThanOrEqual":"6.16.*","status":"unaffected","versionType":"semver"},{"version":"6.17","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":"4.8","versionEndExcluding":"5.4.297"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"5.10.241"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"5.15.190"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.1.162"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.6.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.12.43"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.15.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.16.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.8","versionEndExcluding":"6.17"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/d0194e391bb493aa6cec56d177b14df6b29188d5"},{"url":"https://git.kernel.org/stable/c/03d0cc6889e02420125510b5444b570f4bbf53d5"},{"url":"https://git.kernel.org/stable/c/cd0e92bb2b7542fb96397ffac639b4f5b099d0cb"},{"url":"https://git.kernel.org/stable/c/4506bcaabe004d07be8ff09116a3024fbd6aa965"},{"url":"https://git.kernel.org/stable/c/ea094f38d387d1b0ded5dee4a3e5720aa4ce0139"},{"url":"https://git.kernel.org/stable/c/7d757f17bc2ef2727994ffa6d5d6e4bc4789a770"},{"url":"https://git.kernel.org/stable/c/fc66772607101bd2030a4332b3bd0ea3b3605250"},{"url":"https://git.kernel.org/stable/c/1bd5214ea681584c5886fea3ba03e49f93a43c0e"},{"url":"https://git.kernel.org/stable/c/fd60d8a086191fe33c2d719732d2482052fa6805"}],"title":"sctp: linearize cloned gso packets in sctp_rcv","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T17:41:48.713Z"}},{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-38718","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-06-10T20:40:36.204042Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-06-11T18:44:03.458Z"}}]}}