CVE-2026-52995: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-735g-xvv4-mj9w",
  "modified" : "2026-07-15T15:32:43Z",
  "published" : "2026-06-24T18:32:42Z",
  "aliases" : [ "CVE-2026-52995" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/rds: zero per-item info buffer before handing it to visitors\n\nrds_for_each_conn_info() and rds_walk_conn_path_info() both hand a\ncaller-allocated on-stack u64 buffer to a per-connection visitor and\nthen copy the full item_len bytes back to user space via\nrds_info_copy() regardless of how much of the buffer the visitor\nactually wrote.\n\nrds_ib_conn_info_visitor() and rds6_ib_conn_info_visitor() only\nwrite a subset of their output struct when the underlying\nrds_connection is not in state RDS_CONN_UP (src/dst addr, tos, sl\nand the two GIDs via explicit memsets). Several u32 fields\n(max_send_wr, max_recv_wr, max_send_sge, rdma_mr_max, rdma_mr_size,\ncache_allocs) and the 2-byte alignment hole between sl and\ncache_allocs remain as whatever stack contents preceded the visitor\ncall and are then memcpy_to_user()'d out to user space.\n\nstruct rds_info_rdma_connection and struct rds6_info_rdma_connection\nare the only rds_info_* structs in include/uapi/linux/rds.h that are\nnot marked __attribute__((packed)), so they have a real alignment\nhole. The other info visitors (rds_conn_info_visitor,\nrds6_conn_info_visitor, rds_tcp_tc_info, ...) write all fields of\ntheir packed output struct today and are not known to be vulnerable,\nbut a future visitor that adds a conditional write-path would have\nthe same bug.\n\nReproduction on a kernel built without CONFIG_INIT_STACK_ALL_ZERO=y:\na local unprivileged user opens AF_RDS, sets SO_RDS_TRANSPORT=IB,\nbinds to a local address on an RDMA-capable netdev (rxe soft-RoCE on\nany netdev is sufficient), sendto()'s any peer on the same subnet\n(fails cleanly but installs an rds_connection in the global hash in\nRDS_CONN_CONNECTING), then calls getsockopt(SOL_RDS,\nRDS_INFO_IB_CONNECTIONS). The returned 68-byte item contains 26\nbytes of stack garbage including kernel text/data pointers:\n\n    0..7   0a 63 00 01 0a 63 00 02     src=10.99.0.1 dst=10.99.0.2\n    8..39  00 ...                      gids (memset-zeroed)\n    40..47 e0 92 a3 81 ff ff ff ff     kernel pointer (max_send_wr)\n    48..55 7f 37 b5 81 ff ff ff ff     kernel pointer (rdma_mr_max)\n    56..59 01 00 08 00                 rdma_mr_size (garbage)\n    60..61 00 00                       tos, sl\n    62..63 00 00                       alignment padding\n    64..67 18 00 00 00                 cache_allocs (garbage)\n\nFix by zeroing the per-item buffer in both rds_for_each_conn_info()\nand rds_walk_conn_path_info() before invoking the visitor. This\ncovers the IPv4/IPv6 IB visitors and hardens all current and future\nvisitors against the same class of bug.\n\nNo functional change for visitors that fully populate their output.\n\nChanges in v2:\n- retarget at the net tree (subject prefix \"[PATCH net v2]\",\n  net/rds: prefix in the title)\n- pick up Reviewed-by tags from Sharath Srinivasan and\n  Allison Henderson",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-52995"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/0797b2e6901827694aa9c34c4c72118c8c97fba1"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/5e67cc262afb384e835c3327e9d954eeaedc6a87"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/81651e9d7dea1c048d2952f57632a042931d7b43"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/912ba2e5704fdb8bc5decda96dfc1a57838f0099"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/91ce1bb6e4194dc2321748f68145359dcf86e350"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/b6ba93a7b71ed443c9843eb12d27ed86f1e52694"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/c7cb9eed8215a790f052f49cdccf577720d2bb62"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/c88eb7e8d8397a8c1db59c425332c5a30b2a1682"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-06-24T17:17:10Z"
  }
}