Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2022-50401: nfsd: under NFSv4.1, fix double svc_xprt_put on rpc_create failure

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.44% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 15fc60aa5bdcf6d5f93000d3d00579fc67632ee0, 3bc8edc98bd43540dbe648e4ef91f443d6d20a24, 4.14.303.
  • Severity is disputed: the assigning authority (CNA) scores it 9.8, NVD 7.8.

Low priority for now. Upgrade to Linux Linux 15fc60aa5bdcf6d5f93000d3d00579fc67632ee0, 3bc8edc98bd43540dbe648e4ef91f443d6d20a24, 4.14.303 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: nfsd: under NFSv4.1, fix double svc_xprt_put on rpc_create failure On error situation `clp->cl_cb_conn.cb_xprt` should not be given a reference to the xprt otherwise both client cleanup and the error handling path of the caller call to put it. Better to delay handing over the reference to a later branch. [ 72.530665] refcount_t: underflow; use-after-free. [ 72.531933] WARNING: CPU: 0 PID: 173 at lib/refcount.c:28 refcount_warn_saturate+0xcf/0x120 [ 72.533075] Modules linked in: nfsd(OE) nfsv4(OE) nfsv3(OE) nfs(OE) lockd(OE) compat_nfs_ssc(OE) nfs_acl(OE) rpcsec_gss_krb5(OE) auth_rpcgss(OE) rpcrdma(OE) dns_resolver fscache netfs grace rdma_cm iw_cm ib_cm sunrpc(OE) mlx5_ib mlx5_core mlxfw pci_hyperv_intf ib_uverbs ib_core xt_MASQUERADE nf_conntrack_netlink nft_counter xt_addrtype nft_compat br_netfilter bridge stp llc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set overlay nf_tables nfnetlink crct10dif_pclmul crc32_pclmul ghash_clmulni_intel xfs serio_raw virtio_net virtio_blk net_failover failover fuse [last unloaded: sunrpc] [ 72.540389] CPU: 0 PID: 173 Comm: kworker/u16:5 Tainted: G OE 5.15.82-dan #1 [ 72.541511] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-3.module+el8.7.0+1084+97b81f61 04/01/2014 [ 72.542717] Workqueue: nfsd4_callbacks nfsd4_run_cb_work [nfsd] [ 72.543575] RIP: 0010:refcount_warn_saturate+0xcf/0x120 [ 72.544299] Code: 55 00 0f 0b 5d e9 01 50 98 00 80 3d 75 9e 39 08 00 0f 85 74 ff ff ff 48 c7 c7 e8 d1 60 8e c6 05 61 9e 39 08 01 e8 f6 51 55 00 <0f> 0b 5d e9 d9 4f 98 00 80 3d 4b 9e 39 08 00 0f 85 4c ff ff ff 48 [ 72.546666] RSP: 0018:ffffb3f841157cf0 EFLAGS: 00010286 [ 72.547393] RAX: 0000000000000026 RBX: ffff89ac6231d478 RCX: 0000000000000000 [ 72.548324] RDX: ffff89adb7c2c2c0 RSI: ffff89adb7c205c0 RDI: ffff89adb7c205c0 [ 72.549271] RBP: ffffb3f841157cf0 R08: 0000000000000000 R09: c0000000ffefffff [ 72.550209] R10: 0000000000000001 R11: ffffb3f841157ad0 R12: ffff89ac6231d180 [ 72.551142] R13: ffff89ac6231d478 R14: ffff89ac40c06180 R15: ffff89ac6231d4b0 [ 72.552089] FS: 0000000000000000(0000) GS:ffff89adb7c00000(0000) knlGS:0000000000000000 [ 72.553175] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 72.553934] CR2: 0000563a310506a8 CR3: 0000000109a66000 CR4: 0000000000350ef0 [ 72.554874] Call Trace: [ 72.555278] <TASK> [ 72.555614] svc_xprt_put+0xaf/0xe0 [sunrpc] [ 72.556276] nfsd4_process_cb_update.isra.11+0xb7/0x410 [nfsd] [ 72.557087] ? update_load_avg+0x82/0x610 [ 72.557652] ? cpuacct_charge+0x60/0x70 [ 72.558212] ? dequeue_entity+0xdb/0x3e0 [ 72.558765] ? queued_spin_unlock+0x9/0x20 [ 72.559358] nfsd4_run_cb_work+0xfc/0x270 [nfsd] [ 72.560031] process_one_work+0x1df/0x390 [ 72.560600] worker_thread+0x37/0x3b0 [ 72.561644] ? process_one_work+0x390/0x390 [ 72.562247] kthread+0x12f/0x150 [ 72.562710] ? set_kthread_struct+0x50/0x50 [ 72.563309] ret_from_fork+0x22/0x30 [ 72.563818] </TASK> [ 72.564189] ---[ end trace 031117b1c72ec616 ]--- [ 72.566019] list_add corruption. next->prev should be prev (ffff89ac4977e538), but was ffff89ac4763e018. (next=ffff89ac4763e018). [ 72.567647] ------------[ cut here ]------------

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Sep 18, 2025
Updated
Aug 5, 2026
EPSS
0.4% · 38th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · Linux
9.8
2.0 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2022-50401

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.4.229 and later · before 4.5
  • linux linux kernel4.9.229 and later · before 4.9.337
  • linux linux kernel4.14.186 and later · before 4.14.303
  • linux linux kernel4.19.130 and later · before 4.19.270
  • linux linux kernel5.4.49 and later · before 5.4.229
  • linux linux kernel5.7.6 and later · before 5.10.163
  • linux linux kernel5.11 and later · before 5.15.86
  • linux linux kernel5.16 and later · before 6.0.16
  • linux linux kernel6.1 and later · before 6.1.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • f5a50e848e4509448b8b91536b5d421722bf154b, c745f9ef3c8cbae70556131eaeaf0f64510243b7, 5.8affected
    • 69151594c72a1748cf93ae5b5fa68d5084253dce and later · before 707bcca9616002d204091ca7c4d1d91151104332affected · git
    • 0c4fb76c4e711d9e4e70ddc6732310a17076175d and later · before 15fc60aa5bdcf6d5f93000d3d00579fc67632ee0affected · git
    • 22c721560ef24003bcb9c3d9c358841dcfa4e212 and later · before 9b4ae8c42d2ff09ed7c5832ccce5684c55e5ed23affected · git
    • e8cac2e3067e8587f8271c2177cc5ca924a61b54 and later · before fddac3b4578d302ac9e51e7f03a9aae6254ae2a3affected · git
    • a4abc6b12eb1f7a533c2e7484cfa555454ff0977 and later · before c1207219a4bfa50121c9345d5d165470d0a82531affected · git
    • a4abc6b12eb1f7a533c2e7484cfa555454ff0977 and later · before a472f069ced8601979f53c13c0cf20236074ed46affected · git
    • a4abc6b12eb1f7a533c2e7484cfa555454ff0977 and later · before e2f9f03e4537f3fcc8fd2bdd3248530c3477a371affected · git
    • a4abc6b12eb1f7a533c2e7484cfa555454ff0977 and later · before d843ebd860c58a38e45527e8ec6516059f4c97f3affected · git
    • a4abc6b12eb1f7a533c2e7484cfa555454ff0977 and later · before 3bc8edc98bd43540dbe648e4ef91f443d6d20a24affected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.4-16.1.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2023-53417Sep 18, 2025 · USB: sl811: fix memory leak with using debugfs_lookup()
    22Monitor
  • ← EarlierCVE-2023-53418Sep 18, 2025 · USB: gadget: lpc32xx_udc: fix memory leak with using debugfs_lookup()
    22Monitor
  • Later →CVE-2022-50402Sep 18, 2025 · drivers/md/md-bitmap: check the return value of md_bitmap_get_counter()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux15fc60aa5bdcf6d5f93000d3d00579fc67632ee0Vendor (CNA)
Linux Linux3bc8edc98bd43540dbe648e4ef91f443d6d20a24Vendor (CNA)
Linux Linux4.14.303Vendor (CNA)
Linux Linux4.19.270Vendor (CNA)
Linux Linux4.5Vendor (CNA)
Linux Linux4.9.337Vendor (CNA)
Linux Linux5.4.229Vendor (CNA)
Linux Linux5.8Vendor (CNA)
Linux Linux707bcca9616002d204091ca7c4d1d91151104332Vendor (CNA)
Linux Linux9b4ae8c42d2ff09ed7c5832ccce5684c55e5ed23Vendor (CNA)
Linux Linuxa472f069ced8601979f53c13c0cf20236074ed46Vendor (CNA)
Linux Linuxc1207219a4bfa50121c9345d5d165470d0a82531Vendor (CNA)
Linux Linuxd843ebd860c58a38e45527e8ec6516059f4c97f3Vendor (CNA)
Linux Linuxe2f9f03e4537f3fcc8fd2bdd3248530c3477a371Vendor (CNA)
Linux Linuxfddac3b4578d302ac9e51e7f03a9aae6254ae2a3Vendor (CNA)
debian:linux6.1.4-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-31608218 days apartsmb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()
    39Monitor
  • CVE-2026-31609218 days apartsmb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
    39Monitor
  • CVE-2026-43011225 days apartnet/x25: Fix potential double free of skb
    39Monitor
  • CVE-2026-43414232 days apartscsi: qla2xxx: Completely fix fcport double free
    39Monitor
  • CVE-2026-52993279 days aparttipc: fix double-free in tipc_buf_append()
    39Monitor
  • CVE-2026-63888304 days apartscsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd()
    39Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-415 · Double Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records