CVE-2021-47481· NVD / CVE Program· CNA Linux

RDMA/mlx5: Initialize the ODP xarray when creating an ODP MR

Noroxi assessment

Priority: Monitor (action score 22/100)

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: 0.18% (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 5.13, 5508546631a0f555d7088203dec2614e41b5106e, 5f6995295f65d1ee6f36d466d26afd98eb797afe.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 5.13, 5508546631a0f555d7088203dec2614e41b5106e, 5f6995295f65d1ee6f36d466d26afd98eb797afe 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: RDMA/mlx5: Initialize the ODP xarray when creating an ODP MR Normally the zero fill would hide the missing initialization, but an errant set to desc_size in reg_create() causes a crash: BUG: unable to handle page fault for address: 0000000800000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 5 PID: 890 Comm: ib_write_bw Not tainted 5.15.0-rc4+ #47 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:mlx5_ib_dereg_mr+0x14/0x3b0 [mlx5_ib] Code: 48 63 cd 4c 89 f7 48 89 0c 24 e8 37 30 03 e1 48 8b 0c 24 eb a0 90 0f 1f 44 00 00 41 56 41 55 41 54 55 53 48 89 fb 48 83 ec 30 <48> 8b 2f 65 48 8b 04 25 28 00 00 00 48 89 44 24 28 31 c0 8b 87 c8 RSP: 0018:ffff88811afa3a60 EFLAGS: 00010286 RAX: 000000000000001c RBX: 0000000800000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000800000000 RBP: 0000000800000000 R08: 0000000000000000 R09: c0000000fffff7ff R10: ffff88811afa38f8 R11: ffff88811afa38f0 R12: ffffffffa02c7ac0 R13: 0000000000000000 R14: ffff88811afa3cd8 R15: ffff88810772fa00 FS: 00007f47b9080740(0000) GS:ffff88852cd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000800000000 CR3: 000000010761e003 CR4: 0000000000370ea0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mlx5_ib_free_odp_mr+0x95/0xc0 [mlx5_ib] mlx5_ib_dereg_mr+0x128/0x3b0 [mlx5_ib] ib_dereg_mr_user+0x45/0xb0 [ib_core] ? xas_load+0x8/0x80 destroy_hw_idr_uobject+0x1a/0x50 [ib_uverbs] uverbs_destroy_uobject+0x2f/0x150 [ib_uverbs] uobj_destroy+0x3c/0x70 [ib_uverbs] ib_uverbs_cmd_verbs+0x467/0xb00 [ib_uverbs] ? uverbs_finalize_object+0x60/0x60 [ib_uverbs] ? ttwu_queue_wakelist+0xa9/0xe0 ? pty_write+0x85/0x90 ? file_tty_write.isra.33+0x214/0x330 ? process_echoes+0x60/0x60 ib_uverbs_ioctl+0xa7/0x110 [ib_uverbs] __x64_sys_ioctl+0x10d/0x8e0 ? vfs_write+0x17f/0x260 do_syscall_64+0x3c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Add the missing xarray initialization and remove the desc_size set.

MediumCVSS 5.5 · v3.1—No exploit Fix available

Denial of service

BDU:2024-10509

Published: May 22, 2024
Updated: Jun 17, 2026
EPSS: 0.1% · 7th percentile
CWE: —

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

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

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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.

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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

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

linux linux kernel5.12.4 and later · before 5.13
linux linux kernel5.13 and later · before 5.14.16
linux linux kernel5.15

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
- 29f91bd26f3ba828a55cb446ecd44caacf0df026, 5.13affected
- a639e66703ee45745dc4057c7c2013ed9e1963a7 and later · before 5f6995295f65d1ee6f36d466d26afd98eb797afeaffected · git
- a639e66703ee45745dc4057c7c2013ed9e1963a7 and later · before 5508546631a0f555d7088203dec2614e41b5106eaffected · git
- 5.12.4 and later · before 5.13affected · semver
- before 5.13not affected · semver
- 5.14.16 and later · up to and including 5.14.*not affected · semver
- 5.15 and laternot affected · original_commit_for_fix

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 5.15.3-1	5.15.3-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

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
CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
83Now

Published before and after this one in the same product

← EarlierCVE-2021-47479May 22, 2024 · staging: rtl8712: fix use-after-free in rtl8712_dl_fw
28Monitor
← EarlierCVE-2021-47480May 22, 2024 · scsi: core: Put LLD module refcnt after SCSI device is released
22Monitor
Later →CVE-2021-47482May 22, 2024 · net: batman-adv: fix error handling
21Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
Linux Linux	5.13	Vendor (CNA)
Linux Linux	5508546631a0f555d7088203dec2614e41b5106e	Vendor (CNA)
Linux Linux	5f6995295f65d1ee6f36d466d26afd98eb797afe	Vendor (CNA)
debian:linux	5.15.3-1 · Debian:12	Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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.

No nightly-computed relations.

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-24-0527 · May 23, 2024(Linux Kernel Güncellemesi)

All national notices →

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: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

—

CVSS vector

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

Fix✗ → ✓Sep 28, 2026, 10:10 PM UTC

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

References

git.kernel.org/stable/c/5508546631a0f555d7088203dec2614e41b5106e

Show all references (1 more)

git.kernel.org/stable/c/5f6995295f65d1ee6f36d466d26afd98eb797afe

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

All records