CVE-2021-47001: xprtrdma: Fix cwnd update ordering
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/ rpcrdmapostrecvs() 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 rpcrdmarepcreate() enough to allow the send side to post a bunch of RPC Calls before the Receive completion handler can invoke ibpostrecv().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.25-1Fixed in 6.12.27-1
Event History
Frequently Asked Questions
What is the severity of CVE-2021-47001?
CVE-2021-47001 is classified as a medium-severity vulnerability in the Linux kernel.
How do I fix CVE-2021-47001?
To fix CVE-2021-47001, upgrade to the patched versions of the Linux kernel: 5.10.223-1, 5.10.226-1, 6.1.123-1, 6.1.119-1, 6.12.10-1, or 6.12.11-1.
What systems are affected by CVE-2021-47001?
CVE-2021-47001 affects various versions of the Linux kernel, specifically those between 5.5 and 5.10.38, as well as other specified versions.
What exploitation capabilities does CVE-2021-47001 provide?
CVE-2021-47001 could potentially allow an attacker to exploit the vulnerability through unauthorized Remote Procedure Calls (RPC).
Is there public knowledge available on CVE-2021-47001?
Details on CVE-2021-47001 can be found in several public repositories and security advisories regarding Linux kernel vulnerabilities.