7.8High

CVE-2026-98524rds: ib: Clear the sg list when mapping an MR fails

Linux Linux Published: (26 days ago)

Description

In the Linux kernel, the following vulnerability has been resolved: rds: ib: Clear the sg list when mapping an MR fails rds_ib_map_frmr() stores the caller's scatterlist in the MR before DMA mapping and registration can fail. On failure, __rds_rdma_map() unpins the pages and frees the scatterlist, but rds_ib_free_frmr() can still return the MR to the pool with the stale pointer set. This leaves the pool with a dangling scatterlist and can lead to local privilege escalation. KASAN detects the resulting use-after-free when the MR is later torn down: BUG: KASAN: slab-use-after-free in __rds_ib_teardown_mr Read of size 8 Call Trace: __rds_ib_teardown_mr rds_ib_unreg_frmr rds_ib_flush_mr_pool rds_ib_flush_mrs rds_free_mr rds_setsockopt Store the scatterlist in the MR only after DMA mapping succeeds. If DMA mapping fails, return directly while the MR fields remain clear; the caller keeps ownership of the scatterlist and its pinned pages. If a later registration step fails, unmap the scatterlist and clear the MR fields before returning.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

VendorProductVersions
Linux Linux 4.6
linux linux kernel 4.6 – < 5.10.271

Ubuntu fixes

  • USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities Ubuntu 24.04 · 13.11.2026 · linux-nvidia-tegra
  • USN-9066-1 Linux kernel (HWE) vulnerabilities Ubuntu 22.04 · 12.11.2026 · linux-hwe-6.8
  • USN-8961-1 Linux kernel vulnerabilities Ubuntu 22.04, 20.04 · 03.11.2026 · linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-azure,...
  • USN-8963-1 Linux kernel (NVIDIA Tegra) vulnerabilities Ubuntu 22.04, 20.04 · 03.11.2026 · linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
  • USN-8959-1 Linux kernel vulnerabilities Ubuntu 26.04, 24.04 · 03.11.2026 · linux, linux-aws, linux-gcp, linux-hwe-7.0, linux-ibm, linux-oracle
  • USN-8960-1 Linux kernel (OEM) vulnerabilities Ubuntu 26.04 · 03.11.2026 · linux-oem-7.0

References and patches