Description

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

NFSD: Limit the number of concurrent async COPY operations

Nothing appears to limit the number of concurrent async COPY
operations that clients can start. In addition, AFAICT each async
COPY can copy an unlimited number of 4MB chunks, so can run for a
long time. Thus IMO async COPY can become a DoS vector.

Add a restriction mechanism that bounds the number of concurrent
background COPY operations. Start simple and try to be fair -- this
patch implements a per-namespace limit.

An async COPY request that occurs while this limit is exceeded gets
NFS4ERR_DELAY. The requesting client can choose to send the request
again after a delay or fall back to a traditional read/write style
copy.

If there is need to make the mechanism more sophisticated, we can
visit that in future patches.

Classification

CVE ID: CVE-2024-49974

CVSS Base Severity: LOW

CVSS Base Score: 0.0

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.06% (scored less or equal to compared to others)

EPSS Date: 2025-02-03 (when was this score calculated)

References

https://git.kernel.org/stable/c/7ea9260874b779637aff6d24c344b8ef4ac862a0
https://git.kernel.org/stable/c/ae267989b7b7933dfedcd26468d0a88fc3a9da9e
https://git.kernel.org/stable/c/b4e21431a0db4854b5023cd5af001be557e6c3db
https://git.kernel.org/stable/c/6a488ad7745b8f64625c6d3a24ce7e448e83f11b
https://git.kernel.org/stable/c/aadc3bbea163b6caaaebfdd2b6c4667fbc726752

Timeline