Bug 2025101 (CVE-2021-4090) - CVE-2021-4090 kernel: Overflow of bmval[bmlen-1] in nfsd4_decode_bitmap function
Summary: CVE-2021-4090 kernel: Overflow of bmval[bmlen-1] in nfsd4_decode_bitmap function
Keywords:
Status: CLOSED NOTABUG
Alias: CVE-2021-4090
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2037043 2049200
Blocks: 2025102 2031058
TreeView+ depends on / blocked
 
Reported: 2021-11-19 20:57 UTC by Pedro Sampaio
Modified: 2023-03-16 13:58 UTC (History)
42 users (show)

Fixed In Version: kernel 5.16 rc2
Doc Type: If docs needed, set a value
Doc Text:
An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, leading to a system integrity and confidentiality threat.
Clone Of:
Environment:
Last Closed: 2023-03-16 13:58:46 UTC
Embargoed:

Attachments (Terms of Use)

Description Pedro Sampaio 2021-11-19 20:57:11 UTC 
An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. 

In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, and write leading to a system integrity and confidentiality threat.

Upstream discussion:

https://lore.kernel.org/linux-nfs/97860.1636837122@crash.local/
https://lore.kernel.org/linux-nfs/163692036074.16710.5678362976688977923.stgit@klimt.1015granger.net/
Comment 11 Product Security DevOps Team 2023-03-16 13:58:42 UTC 
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2021-4090
Note You need to log in before you can comment on or make changes to this bug.