{"id":"AZL-73893","summary":"CVE-2025-38718 affecting package kernel for versions less than 5.15.200.1-1","details":"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().","modified":"2026-04-01T05:22:21.174220Z","published":"2025-09-04T16:15:41Z","upstream":["CVE-2025-38718"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38718"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-73893.json"}}],"schema_version":"1.7.5"}