{"id":"CVE-2026-31425","summary":"rds: ib: reject FRMR registration before IB connection is established","details":"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-\u003ec_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-\u003ei_cm_id-\u003eqp 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.","modified":"2026-07-09T18:30:32.084738922Z","published":"2026-04-13T13:40:28.911Z","related":["SUSE-SU-2026:2068-1","SUSE-SU-2026:21834-1","SUSE-SU-2026:21841-1","SUSE-SU-2026:21845-1","SUSE-SU-2026:21860-1","SUSE-SU-2026:21876-1","SUSE-SU-2026:21877-1","SUSE-SU-2026:21916-1","SUSE-SU-2026:21919-1","SUSE-SU-2026:2217-1","SUSE-SU-2026:2238-1","openSUSE-SU-2026:20826-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31425.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/23e07c340c445f0ebff7757ba15434cb447eb662"},{"type":"WEB","url":"https://git.kernel.org/stable/c/450ec93c0f172374acbf236f1f5f02d53650aa2d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/47de5b73db3b88f45c107393f26aeba26e9e8fae"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6b0a8de67ac0c74e1a7df92b73c862cb36780dfc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/82e4a3b56b23b844802056c9e75a39d24169b0a4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a54ecccfae62c5c85259ae5ea5d9c20009519049"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a5bfd14c9a299e6db4add4440430ee5e010b03ad"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c506456ebf84c50ed9327473d4e9bd905def212b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31425.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31425"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1659185fb4d0025835eb2058a141f0746c5cab00"},{"fixed":"c506456ebf84c50ed9327473d4e9bd905def212b"},{"fixed":"82e4a3b56b23b844802056c9e75a39d24169b0a4"},{"fixed":"450ec93c0f172374acbf236f1f5f02d53650aa2d"},{"fixed":"6b0a8de67ac0c74e1a7df92b73c862cb36780dfc"},{"fixed":"a5bfd14c9a299e6db4add4440430ee5e010b03ad"},{"fixed":"23e07c340c445f0ebff7757ba15434cb447eb662"},{"fixed":"47de5b73db3b88f45c107393f26aeba26e9e8fae"},{"fixed":"a54ecccfae62c5c85259ae5ea5d9c20009519049"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31425.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.6.0"},{"fixed":"5.10.253"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.203"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.168"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.134"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.81"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.22"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31425.json"}}],"schema_version":"1.7.5"}