{
  "threat_severity" : "Moderate",
  "public_date" : "2026-04-13T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: rds: ib: reject FRMR registration before IB connection is established",
    "id" : "2457836",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2457836"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-476",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nrds: ib: reject FRMR registration before IB connection is established\nrds_ib_get_mr() extracts the rds_ib_connection from conn->c_transport_data\nand passes it to rds_ib_reg_frmr() for FRWR memory registration. On a\nfresh outgoing connection, ic is allocated in rds_ib_conn_alloc() with\ni_cm_id = NULL because the connection worker has not yet called\nrds_ib_conn_path_connect() to create the rdma_cm_id. When sendmsg() with\nRDS_CMSG_RDMA_MAP is called on such a connection, the sendmsg path parses\nthe control message before any connection establishment, allowing\nrds_ib_post_reg_frmr() to dereference ic->i_cm_id->qp and crash the\nkernel.\nThe existing guard in rds_ib_reg_frmr() only checks for !ic (added in\ncommit 9e630bcb7701), which does not catch this case since ic is allocated\nearly and is always non-NULL once the connection object exists.\nKASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\nRIP: 0010:rds_ib_post_reg_frmr+0x50e/0x920\nCall Trace:\nrds_ib_post_reg_frmr (net/rds/ib_frmr.c:167)\nrds_ib_map_frmr (net/rds/ib_frmr.c:252)\nrds_ib_reg_frmr (net/rds/ib_frmr.c:430)\nrds_ib_get_mr (net/rds/ib_rdma.c:615)\n__rds_rdma_map (net/rds/rdma.c:295)\nrds_cmsg_rdma_map (net/rds/rdma.c:860)\nrds_sendmsg (net/rds/send.c:1363)\n____sys_sendmsg\ndo_syscall_64\nAdd a check in rds_ib_get_mr() that verifies ic, i_cm_id, and qp are all\nnon-NULL before proceeding with FRMR registration, mirroring the guard\nalready present in rds_ib_post_inv(). Return -ENODEV when the connection\nis not ready, which the existing error handling in rds_cmsg_send() converts\nto -EAGAIN for userspace retry and triggers rds_conn_connect_if_down() to\nstart the connection worker.", "A flaw was found in the Linux kernel. A local user can trigger a null pointer dereference in the Reliable Datagram Sockets (RDS) over InfiniBand (IB) component. This occurs when `sendmsg()` with `RDS_CMSG_RDMA_MAP` is called on a new outgoing connection before the IB connection is fully established. Successful exploitation leads to a kernel crash, resulting in a Denial of Service (DoS)." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-31425\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31425\nhttps://lore.kernel.org/linux-cve-announce/2026041357-CVE-2026-31425-40d3@gregkh/T" ],
  "name" : "CVE-2026-31425",
  "csaw" : false
}