CVE-2024-36476

In the Linux kernel, the following vulnerability has been resolved:

RDMA/rtrs: Ensure 'ib_sge list' is accessible

Move the declaration of the 'ib_sge list' variable outside the 'always_invalidate' block to ensure it remains accessible for use throughout the function.

Previously, 'ib_sge list' was declared within the 'always_invalidate' block, limiting its accessibility, then caused a 'BUG: kernel NULL pointer dereference'[1]. ? __die_body.cold+0x19/0x27 ? page_fault_oops+0x15a/0x2d0 ? search_module_extables+0x19/0x60 ? search_bpf_extables+0x5f/0x80 ? exc_page_fault+0x7e/0x180 ? asm_exc_page_fault+0x26/0x30 ? memcpy_orig+0xd5/0x140 rxe_mr_copy+0x1c3/0x200 [rdma_rxe] ? rxe_pool_get_index+0x4b/0x80 [rdma_rxe] copy_data+0xa5/0x230 [rdma_rxe] rxe_requester+0xd9b/0xf70 [rdma_rxe] ? finish_task_switch.isra.0+0x99/0x2e0 rxe_sender+0x13/0x40 [rdma_rxe] do_task+0x68/0x1e0 [rdma_rxe] process_one_work+0x177/0x330 worker_thread+0x252/0x390 ? __pfx_worker_thread+0x10/0x10

This change ensures the variable is available for subsequent operations that require it.

[1] https://lore.kernel.org/linux-rdma/[email protected]/

Red Hat has evaluated this issue as having Moderate severity because exploitation requires RDMA networking hardware or specialized software emulation to be active, limiting exposure to environments running RDMA transport services. The RDMA Transport Server driver is not loaded by default in standard enterprise deployments and requires specific administrative setup to handle remote storage traffic. While triggering this defect results in a kernel crash and denial of service, it does not lead to confidentiality loss or unauthorized privilege escalation.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.