nfsd: clear opcnt on compound arg release to prevent OOB read
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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
- Fix
- Fixed in 6.12.109, 6.18.50, 7.2.4
- 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
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: clear opcnt on compound arg release to prevent OOB read nfsd4_release_compoundargs() resets args->ops to the inline iops[8] array when the dynamically-allocated ops buffer is freed, but leaves args->opcnt at its original value (which can be up to 200 for NFSv4.1+ compounds). If rq_status_counter is stuck at an odd value (which can happen when nfsd_dispatch() hits an error path after setting it odd), the RPC status dumpit handler reads min(opcnt, 16) entries from args->ops[]. Since iops only has 8 elements and is the last field in struct nfsd4_compoundargs, reading indices 8-15 accesses adjacent slab memory and leaks it to userspace via netlink. Zero opcnt unconditionally in nfsd4_release_compoundargs() so stale compound metadata is never exposed through the status interface. [ cel: Remove the kvfree_rcu_mightsleep() sleep from the exposure window ]
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From bd9d6a3efa9709e653aafbeb859289feccb8e70c · fixed in 58bcdfb2b2e412088839ae740b1a95154dc0b8d0; From bd9d6a3efa9709e653aafbeb859289feccb8e70c · fixed in e879148867bd4c4cac42e063ffaffa187dddc6fe; From bd9d6a3efa9709e653aafbeb859289feccb8e70c · fixed in c1a4f7b1848f95302df598217e1c7a1410c2d0c5; From bd9d6a3efa9709e653aafbeb859289feccb8e70c · fixed in ae4c38555e81563b8dc5eae55ffd70f0ea97aa5a
- Linux Linux
6.7
- KernelLinux
From 6.7.0 · fixed in 6.12.109; From 6.13.0 · fixed in 6.18.50; From 6.19.0 · fixed in 7.2.4