{"id":"CVE-2026-46114","summary":"RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads\n\natomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c\nunconditionally dereferences 8 bytes at payload_addr(pkt):\n\n    value = *(u64 *)payload_addr(pkt);\n\ncheck_rkey() previously accepted an ATOMIC_WRITE request with pktlen ==\nresid == 0 because the length validation only compared pktlen against\nresid. A remote initiator that sets the RETH length to 0 therefore reaches\natomic_write_reply() with a zero-byte logical payload, and the responder\nreads sizeof(u64) bytes from past the logical end of the packet into\nskb-\u003ehead tailroom, then writes those 8 bytes into the attacker's MR via\nrxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel\ntailroom per probe (the other 4 bytes are the packet's own trailing ICRC).\n\nIBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is\nprotocol-invalid. Hoist a strict length check into check_rkey() so the\nresponder never reaches the unchecked dereference, and keep the existing\nWRITE-family length logic for the normal RDMA WRITE path.\n\nReproduced on mainline with an unmodified rxe driver: a sustained\nzero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer\nbytes into the attacker's MR, including recognisable kernel strings and\npartial kernel-direct-map pointer words.  With this patch applied the\nresponder rejects the PDU and the MR stays all-zero.","modified":"2026-07-15T01:49:15.466588884Z","published":"2026-05-28T09:35:24.638Z","related":["SUSE-SU-2026:22099-1","SUSE-SU-2026:22108-1","SUSE-SU-2026:22112-1","SUSE-SU-2026:22117-1","SUSE-SU-2026:22127-1","SUSE-SU-2026:22137-1","SUSE-SU-2026:22433-1","SUSE-SU-2026:22458-1","SUSE-SU-2026:2310-1","SUSE-SU-2026:2482-1","SUSE-SU-2026:2591-1","openSUSE-SU-2026:10954-1","openSUSE-SU-2026:20965-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46114.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/105bf79a23b85cf3a761d18a4f3e10ce88526bc1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1114c87aa6f195cf07da55a27b2122ae26557b26"},{"type":"WEB","url":"https://git.kernel.org/stable/c/539cabb7b2d8ba70f55bba91db55faef11c2a6d7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7ec1ed4747f5f99f8b797bb438c5efd36079fad5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d415fce3fcde6d7aeea6c25362a395b905811452"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46114.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46114"},{"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":"034e285f8b99062a0cf29112e1232154a6a44aa5"},{"fixed":"539cabb7b2d8ba70f55bba91db55faef11c2a6d7"},{"fixed":"d415fce3fcde6d7aeea6c25362a395b905811452"},{"fixed":"105bf79a23b85cf3a761d18a4f3e10ce88526bc1"},{"fixed":"7ec1ed4747f5f99f8b797bb438c5efd36079fad5"},{"fixed":"1114c87aa6f195cf07da55a27b2122ae26557b26"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46114.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.140"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.88"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.30"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-46114.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}