CVE-2025-38718

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> sctp: linearize cloned gso packets in sctp_rcv<br /> <br /> A cloned head skb still shares these frag skbs in fraglist with the<br /> original head skb. It&amp;#39;s not safe to access these frag skbs.<br /> <br /> syzbot reported two use-of-uninitialized-memory bugs caused by this:<br /> <br /> BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211<br /> sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211<br /> sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998<br /> sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88<br /> sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331<br /> sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122<br /> __release_sock+0x1da/0x330 net/core/sock.c:3106<br /> release_sock+0x6b/0x250 net/core/sock.c:3660<br /> sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360<br /> sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885<br /> sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031<br /> inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851<br /> sock_sendmsg_nosec net/socket.c:718 [inline]<br /> <br /> and<br /> <br /> BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987<br /> sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987<br /> sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88<br /> sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331<br /> sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148<br /> __release_sock+0x1d3/0x330 net/core/sock.c:3213<br /> release_sock+0x6b/0x270 net/core/sock.c:3767<br /> sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367<br /> sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886<br /> sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032<br /> inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851<br /> sock_sendmsg_nosec net/socket.c:712 [inline]<br /> <br /> This patch fixes it by linearizing cloned gso packets in sctp_rcv().