nfs/localio: must clear res.replen in nfs_local_read_done
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
In the Linux kernel, the following vulnerability has been resolved: nfs/localio: must clear res.replen in nfs_local_read_done Otherwise memory corruption can occur due to NFSv3 LOCALIO reads leaving garbage in res.replen: • nfs3_read_done() copies that into server->read_hdrsize; from there nfs3_proc_read_setup() copies it to args.replen in new requests. • nfs3_xdr_enc_read3args() passes that to rpc_prepare_reply_pages() which includes it in hdrsize for xdr_init_pages, so that rq_rcv_buf contains a ridiculous len. • This is copied to rq_private_buf and xs_read_stream_request() eventually passes the kvec to sock_recvmsg() which receives incoming data into entirely the wrong place. This is easily reproduced with NFSv3 LOCALIO that is servicing reads when it is made to pivot back to using normal RPC. This switch back to using normal NFSv3 with RPC can occur for a few reasons but this issue was exposed with a test that stops and then restarts the NFSv3 server while LOCALIO is performing heavy read IO.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
6.12