CVE-2021-47585: btrfs: fix memory leak in __add_inode_ref()
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: 0.25% (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 005d9292b5b2e71a009f911bd85d755009b37242, 493ff661d434d6bdf02e3a21adae04d7a0b4265d, f35838a6930296fc1988764cfa54cb3f705c0665.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 005d9292b5b2e71a009f911bd85d755009b37242, 493ff661d434d6bdf02e3a21adae04d7a0b4265d, f35838a6930296fc1988764cfa54cb3f705c0665 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: btrfs: fix memory leak in __add_inode_ref() Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(), but when the function returns in line 1184 (#4) victim_name allocated by line 1169 (#3) is not freed, which will lead to a memory leak. There is a similar snippet of code in this function as allocating a memory chunk for victim_name in line 1104 (#1) as well as releasing the memory in line 1116 (#2). We should kfree() victim_name when the return value of backref_in_log() is less than zero and before the function returns in line 1184 (#4). 1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans, 1058 struct btrfs_root *root, 1059 struct btrfs_path *path, 1060 struct btrfs_root *log_root, 1061 struct btrfs_inode *dir, 1062 struct btrfs_inode *inode, 1063 u64 inode_objectid, u64 parent_objectid, 1064 u64 ref_index, char *name, int namelen, 1065 int *search_done) 1066 { 1104 victim_name = kmalloc(victim_name_len, GFP_NOFS); // #1: kmalloc (victim_name-1) 1105 if (!victim_name) 1106 return -ENOMEM; 1112 ret = backref_in_log(log_root, &search_key, 1113 parent_objectid, victim_name, 1114 victim_name_len); 1115 if (ret < 0) { 1116 kfree(victim_name); // #2: kfree (victim_name-1) 1117 return ret; 1118 } else if (!ret) { 1169 victim_name = kmalloc(victim_name_len, GFP_NOFS); // #3: kmalloc (victim_name-2) 1170 if (!victim_name) 1171 return -ENOMEM; 1180 ret = backref_in_log(log_root, &search_key, 1181 parent_objectid, victim_name, 1182 victim_name_len); 1183 if (ret < 0) { 1184 return ret; // #4: missing kfree (victim_name-2) 1185 } else if (!ret) { 1241 return 0; 1242 }
- Published
- Jun 19, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.2% · 16th percentile
- CWE
- CWE-401
Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
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.
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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.
We use this product, ask for helpAffected 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 kernel5.5 and later · before 5.10.88
- linux linux kernel5.11 and later · before 5.15.11
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
- 5.5affected
- d3316c8233bb05e0dd855d30aac347bb8ad76ee4 and later · before 005d9292b5b2e71a009f911bd85d755009b37242affected · git
- d3316c8233bb05e0dd855d30aac347bb8ad76ee4 and later · before 493ff661d434d6bdf02e3a21adae04d7a0b4265daffected · git
- d3316c8233bb05e0dd855d30aac347bb8ad76ee4 and later · before f35838a6930296fc1988764cfa54cb3f705c0665affected · git
- before 5.5not affected · semver
- 5.10.88 and later · up to and including 5.10.*not affected · semver
- 5.15.11 and later · up to and including 5.15.*not affected · semver
- 5.16 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 5.15.15-1 | 5.15.15-1 |
| openSUSE:Leap 15.5 | kernel-azure | before 5.14.21-150500.33.60.1 | 5.14.21-150500.33.60.1 |
| openSUSE:Leap 15.5 | kernel-rt | before 5.14.21-150500.13.61.1 | 5.14.21-150500.13.61.1 |
| openSUSE:Leap 15.5 | kernel-rt_debug | before 5.14.21-150500.13.61.1 | 5.14.21-150500.13.61.1 |
| openSUSE:Leap 15.5 | kernel-source-azure | before 5.14.21-150500.33.60.1 | 5.14.21-150500.33.60.1 |
| openSUSE:Leap 15.5 | kernel-source-rt | before 5.14.21-150500.13.61.1 | 5.14.21-150500.13.61.1 |
| openSUSE:Leap 15.5 | kernel-syms-azure | before 5.14.21-150500.33.60.1 | 5.14.21-150500.33.60.1 |
| openSUSE:Leap 15.5 | kernel-syms-rt | before 5.14.21-150500.13.61.1 | 5.14.21-150500.13.61.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-64kb | before 5.14.21-150400.24.128.1 | 5.14.21-150400.24.128.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-docs | before 5.14.21-150400.24.128.1 | 5.14.21-150400.24.128.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-obs-build | before 5.14.21-150400.24.128.1 | 5.14.21-150400.24.128.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | before 5.14.21-150400.24.128.1 | 5.14.21-150400.24.128.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-syms | before 5.14.21-150400.24.128.1 | 5.14.21-150400.24.128.1 |
| SUSE:Linux Enterprise Live Patching 15 SP4 | kernel-livepatch-SLE15-SP4_Update_29 | before 1-150400.9.3.1 | 1-150400.9.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5-RT_Update_17 | before 1-150500.11.3.1 | 1-150500.11.3.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default | before 5.14.21-150400.24.128.1 | 5.14.21-150400.24.128.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-default-base | before 5.14.21-150400.24.128.1.150400.24.62.1 | 5.14.21-150400.24.128.1.150400.24.62.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-rt | before 5.14.21-150400.15.88.1 | 5.14.21-150400.15.88.1 |
| SUSE:Linux Enterprise Micro 5.3 | kernel-source-rt | before 5.14.21-150400.15.88.1 | 5.14.21-150400.15.88.1 |
| SUSE:Linux Enterprise Micro 5.5 | kernel-rt | before 5.14.21-150500.13.61.1 | 5.14.21-150500.13.61.1 |
| SUSE:Linux Enterprise Micro 5.5 | kernel-source-rt | before 5.14.21-150500.13.61.1 | 5.14.21-150500.13.61.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | kernel-azure | before 5.14.21-150500.33.60.1 | 5.14.21-150500.33.60.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | kernel-source-azure | before 5.14.21-150500.33.60.1 | 5.14.21-150500.33.60.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | kernel-syms-azure | before 5.14.21-150500.33.60.1 | 5.14.21-150500.33.60.1 |
+3
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- 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 KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2021-47583Jun 19, 2024 · media: mxl111sf: change mutex_init() location22Monitor
- ← EarlierCVE-2021-47584Jun 19, 2024 · iocost: Fix divide-by-zero on donation from low hweight cgroup22Monitor
- Later →CVE-2021-47586Jun 19, 2024 · net: stmmac: dwmac-rk: fix oob read in rk_gmac_setup22Monitor
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 | 005d9292b5b2e71a009f911bd85d755009b37242 | Vendor (CNA) |
| Linux Linux | 493ff661d434d6bdf02e3a21adae04d7a0b4265d | Vendor (CNA) |
| Linux Linux | f35838a6930296fc1988764cfa54cb3f705c0665 | Vendor (CNA) |
| debian:linux | 5.15.15-1 · Debian:12 | Package registry (OSV) |
| opensuse:kernel-azure | 5.14.21-150500.33.60.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-rt | 5.14.21-150500.13.61.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-rt_debug | 5.14.21-150500.13.61.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-source-azure | 5.14.21-150500.33.60.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-source-rt | 5.14.21-150500.13.61.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-syms-azure | 5.14.21-150500.33.60.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| opensuse:kernel-syms-rt | 5.14.21-150500.13.61.1 · openSUSE:Leap 15.5 | Package registry (OSV) |
| suse:kernel-64kb | 5.14.21-150400.24.128.1 · SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | Package registry (OSV) |
| suse:kernel-azure | 5.14.21-150500.33.60.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | Package registry (OSV) |
| suse:kernel-default | 5.14.21-150400.24.128.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-default-base | 5.14.21-150400.24.128.1.150400.24.62.1 · SUSE:Linux Enterprise Micro 5.3 | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP4_Update_29 | 1-150400.9.3.1 · SUSE:Linux Enterprise Live Patching 15 SP4 | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP5-RT_Update_17 | 1-150500.11.3.1 · SUSE:Linux Enterprise Live Patching 15 SP5 | Package registry (OSV) |
| suse:kernel-rt | 5.14.21-150500.13.61.1 · SUSE:Linux Enterprise Micro 5.5 | Package registry (OSV) |
| suse:kernel-rt_debug | 5.14.21-150500.13.61.1 · SUSE:Real Time Module 15 SP5 | Package registry (OSV) |
| suse:kernel-source-azure | 5.14.21-150500.33.60.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | Package registry (OSV) |
| suse:kernel-source-rt | 5.14.21-150500.13.61.1 · SUSE:Linux Enterprise Micro 5.5 | Package registry (OSV) |
| suse:kernel-syms-azure | 5.14.21-150500.33.60.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | Package registry (OSV) |
| suse:kernel-syms-rt | 5.14.21-150500.13.61.1 · SUSE:Real Time Module 15 SP5 | 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.
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 researchersFinders, 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-24-0733 · Jun 24, 2024(Linux Kernel Güncellemesi)
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)
CWE-401 · Missing Release of Memory after Effective LifetimeCVSS 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✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.