{"cve":"CVE-2026-31425","nvd":{"published":"2026-04-13T14:16:12.420","modified":"2026-06-17T10:33:41.583","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrds: ib: reject FRMR registration before IB connection is established\n\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.\n\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.\n\n KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\n RIP: 0010:rds_ib_post_reg_frmr+0x50e/0x920\n Call Trace:\n  rds_ib_post_reg_frmr (net/rds/ib_frmr.c:167)\n  rds_ib_map_frmr (net/rds/ib_frmr.c:252)\n  rds_ib_reg_frmr (net/rds/ib_frmr.c:430)\n  rds_ib_get_mr (net/rds/ib_rdma.c:615)\n  __rds_rdma_map (net/rds/rdma.c:295)\n  rds_cmsg_rdma_map (net/rds/rdma.c:860)\n  rds_sendmsg (net/rds/send.c:1363)\n  ____sys_sendmsg\n  do_syscall_64\n\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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/23e07c340c445f0ebff7757ba15434cb447eb662","https://git.kernel.org/stable/c/450ec93c0f172374acbf236f1f5f02d53650aa2d","https://git.kernel.org/stable/c/47de5b73db3b88f45c107393f26aeba26e9e8fae","https://git.kernel.org/stable/c/6b0a8de67ac0c74e1a7df92b73c862cb36780dfc","https://git.kernel.org/stable/c/82e4a3b56b23b844802056c9e75a39d24169b0a4"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:30:49.762551342+00:00"},"epss":{"cve":"CVE-2026-31425","score":0.00114,"percentile":0.0147,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}