---
id: CVE-2026-98524
title: 'rds: ib: Clear the sg list when mapping an MR fails'
summary: |-
  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 failur…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    1be3211e6ac77adbb1eac01314d989d243b32c59
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    c42d316163f89cd23de2f3e24558177a8c29bad8
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    8dca3c81344532a7f05edb3d12f31f3009410a90
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    49ba5ed0129906e0362c2e4b5e21c89b2a41e115
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    4468df5bcdef959fd96494e9968f323561a45f4c
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    e2ee0616260080376123997488b5cf8a3870b8d9
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    b36d32f30c3f1e58e3a5ae79d0f52836a316b36e
  - >-
    Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 <
    58eb1b3325edac42dc6df72c80962bd53a3c8ca7
  - Linux 4.6
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:17:41.420Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98524'
references:
  - url: 'https://git.kernel.org/stable/c/1be3211e6ac77adbb1eac01314d989d243b32c59'
  - url: 'https://git.kernel.org/stable/c/c42d316163f89cd23de2f3e24558177a8c29bad8'
  - url: 'https://git.kernel.org/stable/c/8dca3c81344532a7f05edb3d12f31f3009410a90'
  - url: 'https://git.kernel.org/stable/c/49ba5ed0129906e0362c2e4b5e21c89b2a41e115'
  - url: 'https://git.kernel.org/stable/c/4468df5bcdef959fd96494e9968f323561a45f4c'
  - url: 'https://git.kernel.org/stable/c/e2ee0616260080376123997488b5cf8a3870b8d9'
  - url: 'https://git.kernel.org/stable/c/b36d32f30c3f1e58e3a5ae79d0f52836a316b36e'
  - url: 'https://git.kernel.org/stable/c/58eb1b3325edac42dc6df72c80962bd53a3c8ca7'
tags:
  - cve.org
ingestedAt: '2026-10-18T15:45:12.281Z'
---

## Overview

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.

## Affected

- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < 1be3211e6ac77adbb1eac01314d989d243b32c59`
- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < c42d316163f89cd23de2f3e24558177a8c29bad8`
- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < 8dca3c81344532a7f05edb3d12f31f3009410a90`
- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < 49ba5ed0129906e0362c2e4b5e21c89b2a41e115`
- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < 4468df5bcdef959fd96494e9968f323561a45f4c`
- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < e2ee0616260080376123997488b5cf8a3870b8d9`
- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < b36d32f30c3f1e58e3a5ae79d0f52836a316b36e`
- `Linux >= 1659185fb4d0025835eb2058a141f0746c5cab00 < 58eb1b3325edac42dc6df72c80962bd53a3c8ca7`
- `Linux 4.6`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.