CVE-2021-47506
See a problem?- Source
- https://nvd.nist.gov/vuln/detail/CVE-2021-47506
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47506.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2021-47506
- Related
- Published
- 2024-05-24T15:15:11Z
- Modified
- 2024-09-18T03:18:50.754992Z
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix use-after-free due to delegation race
A delegation break could arrive as soon as we've called vfssetlease. A delegation break runs a callback which immediately (in nfsd4cbrecallprepare) adds the delegation to delrecalllru. If we then exit nfs4setdelegation without hashing the delegation, it will be freed as soon as the callback is done with it, without ever being removed from delrecalllru.
Symptoms show up later as use-after-free or list corruption warnings, usually in the laundromat thread.
I suspect aba2072f4523 "nfsd: grant read delegations to clients holding writes" made this bug easier to hit, but I looked as far back as v3.0 and it looks to me it already had the same problem. So I'm not sure where the bug was introduced; it may have been there from the beginning.
- References
-
- https://git.kernel.org/stable/c/04a8d07f3d58308b92630045560799a3faa3ebce
- https://git.kernel.org/stable/c/148c816f10fd11df27ca6a9b3238cdd42fa72cd3
- https://git.kernel.org/stable/c/2becaa990b93cbd2928292c0b669d3abb6cf06d4
- https://git.kernel.org/stable/c/33645d3e22720cac1e4548f8fef57bf0649536ee
- https://git.kernel.org/stable/c/348714018139c39533c55661a0c7c990671396b4
- https://git.kernel.org/stable/c/548ec0805c399c65ed66c6641be467f717833ab5
- https://git.kernel.org/stable/c/e0759696de6851d7536efddfdd2dfed4c4df1f09
- https://git.kernel.org/stable/c/eeb0711801f5e19ef654371b627682aed3b11373
- https://security-tracker.debian.org/tracker/CVE-2021-47506
Affected packages
Debian:11 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Debian:12 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source
Debian:13 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source