CVE-2021-47001 Affecting kernel-preempt package, versions <5.3.18-150300.59.158.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.05% (18th percentile)

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  • Snyk IDSNYK-SLES153-KERNELPREEMPT-7721356
  • published20 Aug 2024
  • disclosed3 May 2024

Introduced: 3 May 2024

CVE-2021-47001  (opens in a new tab)

How to fix?

Upgrade SLES:15.3 kernel-preempt to version 5.3.18-150300.59.158.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-preempt package and not the kernel-preempt package as distributed by SLES. See How to fix? for SLES:15.3 relevant fixed versions and status.

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

xprtrdma: Fix cwnd update ordering

After a reconnect, the reply handler is opening the cwnd (and thus enabling more RPC Calls to be sent) /before/ rpcrdma_post_recvs() can post enough Receive WRs to receive their replies. This causes an RNR and the new connection is lost immediately.

The race is most clearly exposed when KASAN and disconnect injection are enabled. This slows down rpcrdma_rep_create() enough to allow the send side to post a bunch of RPC Calls before the Receive completion handler can invoke ib_post_recv().

CVSS Scores

version 3.1