In 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.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 4.6 | 5.10.253 |
| linux / linux_kernel | 5.11 | 5.15.203 |
| linux / linux_kernel | 5.16 | 6.1.168 |
| linux / linux_kernel | 6.2 | 6.6.134 |
| linux / linux_kernel | 6.7 | 6.12.81 |
| linux / linux_kernel | 6.13 | 6.18.22 |
| linux / linux_kernel | 6.19 | 6.19.12 |
| linux / linux_kernel | 7.0-rc1 | 7.0-rc1.x |
| linux / linux_kernel | 7.0-rc2 | 7.0-rc2.x |
| linux / linux_kernel | 7.0-rc3 | 7.0-rc3.x |
| linux / linux_kernel | 7.0-rc4 | 7.0-rc4.x |
| linux / linux_kernel | 7.0-rc5 | 7.0-rc5.x |
| linux / linux_kernel | 7.0-rc6 | 7.0-rc6.x |
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
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Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
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