GHSA-242H-4QQP-HPG2
Vulnerability from github – Published: 2026-04-13 15:31 – Updated: 2026-04-18 09:30In the Linux kernel, the following vulnerability has been resolved:
rds: ib: reject FRMR registration before IB connection is established
rds_ib_get_mr() extracts the rds_ib_connection from conn->c_transport_data and passes it to rds_ib_reg_frmr() for FRWR memory registration. On a fresh outgoing connection, ic is allocated in rds_ib_conn_alloc() with i_cm_id = NULL because the connection worker has not yet called rds_ib_conn_path_connect() to create the rdma_cm_id. When sendmsg() with RDS_CMSG_RDMA_MAP is called on such a connection, the sendmsg path parses the control message before any connection establishment, allowing rds_ib_post_reg_frmr() to dereference ic->i_cm_id->qp and crash the kernel.
The existing guard in rds_ib_reg_frmr() only checks for !ic (added in commit 9e630bcb7701), which does not catch this case since ic is allocated early and is always non-NULL once the connection object exists.
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:rds_ib_post_reg_frmr+0x50e/0x920 Call Trace: rds_ib_post_reg_frmr (net/rds/ib_frmr.c:167) rds_ib_map_frmr (net/rds/ib_frmr.c:252) rds_ib_reg_frmr (net/rds/ib_frmr.c:430) rds_ib_get_mr (net/rds/ib_rdma.c:615) __rds_rdma_map (net/rds/rdma.c:295) rds_cmsg_rdma_map (net/rds/rdma.c:860) rds_sendmsg (net/rds/send.c:1363) ____sys_sendmsg do_syscall_64
Add a check in rds_ib_get_mr() that verifies ic, i_cm_id, and qp are all non-NULL before proceeding with FRMR registration, mirroring the guard already present in rds_ib_post_inv(). Return -ENODEV when the connection is not ready, which the existing error handling in rds_cmsg_send() converts to -EAGAIN for userspace retry and triggers rds_conn_connect_if_down() to start the connection worker.
{
"affected": [],
"aliases": [
"CVE-2026-31425"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-13T14:16:12Z",
"severity": null
},
"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.",
"id": "GHSA-242h-4qqp-hpg2",
"modified": "2026-04-18T09:30:20Z",
"published": "2026-04-13T15:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31425"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
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Nomenclature
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