CVE-2021-47001

xprtrdma: Fix cwnd update ordering

MEDIUM
4.7
CVSS Score
Published: February 28, 2024 at 08:13 AM UTC
Updated: August 5, 2026 at 09:24 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM4.7
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

Description

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().

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≥ 5.4.135.11 ≤ v < 5.11.225.12 ≤ v < 5.12.55.4.13 ≤ v < 5.55.5 ≤ v < 5.10.385.5 ≤ v < 5.11.225.5 ≤ v < 5.12.55.5 ≤ v < 5.132ae50ad68cd79224198b525f7bd645c9da98b6ff3791c5982ba1eebf2900ee7ca7b9a89619c26d545.4.135.5
Vendor states this is fixed in 19b5fa9489b5706bc878c3a522a7f771079e2fa0 (fixed)
Vendor states this is fixed in 35d8b10a25884050bb3b0149b62c3818ec59f77c (fixed)
Vendor states this is fixed in 8834ecb5df22b7ff3c9b0deba7726579bb613f95 (fixed)
Vendor states this is fixed in eddae8be7944096419c2ae29477a45f767d0fcd4 (fixed)
Vendor states this is fixed in 5.10.38 (unaffected)
Vendor states this is fixed in 5.11.22 (unaffected)
Vendor states this is fixed in 5.12.5 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)
Vendor states this is fixed in 5.5 (unaffected)

References (5)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/19b5fa9489b5706bc878c3a522a7f771079e2fa0
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/35d8b10a25884050bb3b0149b62c3818ec59f77c
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/8834ecb5df22b7ff3c9b0deba7726579bb613f95
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/eddae8be7944096419c2ae29477a45f767d0fcd4
Source: af854a3a-2127-422b-91ae-364da2661108
https://security.netapp.com/advisory/ntap-20250411-0001/

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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