CVE-2021-47179: NFSv4: Fix a NULL pointer dereference in pnfs_mark_matching_lsegs_return()
Vulnerability summary
CVE-2021-47179 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.68% chance of exploitation in the next 30 days, higher than 52.2% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 6Timeline
- 25-03-2024PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix a NULL pointer dereference in pnfs_mark_matching_lsegs_return() Commit de144ff4234f changes _pnfs_return_layout() to call pnfs_mark_matching_lsegs_return() passing NULL as the struct pnfs_layout_range argument. Unfortunately, pnfs_mark_matching_lsegs_return() doesn't check if we have a value here before dereferencing it, causing an oops. I'm able to hit this crash consistently when running connectathon basic tests on NFS v4.1/v4.2 against Ontap.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.68%
Chance of exploitation in the next 30 days
Percentile
52%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.68% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu79 products
- linux< 5.4.0-80.90
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.4.0-1054.57
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 80e34f4957ec3010c85f9bb0b568a8d46acdf535, < 4e1ba532dbc1a0e19fc2458d74ab8d98680c4e42 | ≥ 7b7b9774643220e53eef58c15bb29bd4182fe053, < 42637ca25c7d7b5a92804a679af5192e8c1a9f48 | ≥ 9ffa7967f9379a0a1b924e9ffeda709d72237da7, < 39785761feadf261bc5101372b0b0bbaf6a94494 | ≥ 6be0e4b59314e4a836495f6ffdc5d2c5b079deeb, < aba3c7795f51717ae316f3566442dee7cc3eeccb | ≥ 2fafe7d5047f98791afd9a1d90d2afb70debc590, < f9890652185b72b8de9ebeb4406037640b6e1b53 | ≥ 7e65ea887d0c0997f3053acd91a027af45e71c5b, < b090d110e66636bca473fd8b98d5c97b555a965a | ≥ de144ff4234f935bd2150108019b5d87a90a8a96, < a421d218603ffa822a0b8045055c03eae394a7eb | 96260bde1ea8ae31a5402fe506abbb8951d5a42c | ≥ 5.11.20, < 5.12 | ≥ 4.9.269, < 4.9.271 | ≥ 4.14.233, < 4.14.235 | ≥ 4.19.191, < 4.19.193 | ≥ 5.4.118, < 5.4.124 | ≥ 5.10.36, < 5.10.42 | ≥ 5.12.3, < 5.12.9
- linux_kernel≥ 4.9.269, < 4.9.271 | ≥ 4.14.233, < 4.14.235 | ≥ 4.19.191, < 4.19.193 | ≥ 5.4.118, < 5.4.124 | ≥ 5.10.36, < 5.10.42 | ≥ 5.12.3, < 5.12.9
Debian1 product
- linux< 5.14.6-1
3 vendors · 82 products
