CVE-2021-47145: btrfs: do not BUG_ON in link_to_fixup_dir
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: 0.26% (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 0eaf383c6a4a83c09f60fd07a1bea9f1a9181611, 0ed102453aa1cd12fefde8f6b60b9519b0b1f003, 6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9fa.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 0eaf383c6a4a83c09f60fd07a1bea9f1a9181611, 0ed102453aa1cd12fefde8f6b60b9519b0b1f003, 6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9fa 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: do not BUG_ON in link_to_fixup_dir While doing error injection testing I got the following panic kernel BUG at fs/btrfs/tree-log.c:1862! invalid opcode: 0000 [#1] SMP NOPTI CPU: 1 PID: 7836 Comm: mount Not tainted 5.13.0-rc1+ #305 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:link_to_fixup_dir+0xd5/0xe0 RSP: 0018:ffffb5800180fa30 EFLAGS: 00010216 RAX: fffffffffffffffb RBX: 00000000fffffffb RCX: ffff8f595287faf0 RDX: ffffb5800180fa37 RSI: ffff8f5954978800 RDI: 0000000000000000 RBP: ffff8f5953af9450 R08: 0000000000000019 R09: 0000000000000001 R10: 000151f408682970 R11: 0000000120021001 R12: ffff8f5954978800 R13: ffff8f595287faf0 R14: ffff8f5953c77dd0 R15: 0000000000000065 FS: 00007fc5284c8c40(0000) GS:ffff8f59bbd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc5287f47c0 CR3: 000000011275e002 CR4: 0000000000370ee0 Call Trace: replay_one_buffer+0x409/0x470 ? btree_read_extent_buffer_pages+0xd0/0x110 walk_up_log_tree+0x157/0x1e0 walk_log_tree+0xa6/0x1d0 btrfs_recover_log_trees+0x1da/0x360 ? replay_one_extent+0x7b0/0x7b0 open_ctree+0x1486/0x1720 btrfs_mount_root.cold+0x12/0xea ? __kmalloc_track_caller+0x12f/0x240 legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 ? vfs_parse_fs_string+0x4d/0x90 legacy_get_tree+0x24/0x40 vfs_get_tree+0x22/0xb0 path_mount+0x433/0xa10 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae We can get -EIO or any number of legitimate errors from btrfs_search_slot(), panicing here is not the appropriate response. The error path for this code handles errors properly, simply return the error.
- Published
- Mar 25, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.2% · 19th percentile
- CWE
- —
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 kernelbefore 4.4.271
- linux linux kernel4.5 and later · before 4.9.271
- linux linux kernel4.10 and later · before 4.14.235
- linux linux kernel4.15 and later · before 4.19.193
- linux linux kernel4.20 and later · before 5.4.124
- linux linux kernel5.5 and later · before 5.10.42
- linux linux kernel5.11 and later · before 5.12.9
- linux linux kernel5.13
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
- 2.6.29affected
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before 76bfd8ac20bebeae599452a03dfc5724c0475dcfaffected · git
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before e934c4ee17b33bafb0444f2f9766cda7166d3c40affected · git
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before 0eaf383c6a4a83c09f60fd07a1bea9f1a9181611affected · git
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before 6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9faaffected · git
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before 0ed102453aa1cd12fefde8f6b60b9519b0b1f003affected · git
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before 7e13db503918820e6333811cdc6f151dcea5090aaffected · git
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before b545442133580dcb2f2496133bf850824d41255caffected · git
- e02119d5a7b4396c5a872582fddc8bd6d305a70a and later · before 91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96daffected · git
- before 2.6.29not affected · semver
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 5.14.6-1 | 5.14.6-1 |
| SUSE:Linux Enterprise High Availability Extension 12 SP5 | kernel-default | before 4.12.14-122.222.1 | 4.12.14-122.222.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_58 | before 1-8.3.1 | 1-8.3.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-rt | before 4.12.14-10.194.1 | 4.12.14-10.194.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-rt_debug | before 4.12.14-10.194.1 | 4.12.14-10.194.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-source-rt | before 4.12.14-10.194.1 | 4.12.14-10.194.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-syms-rt | before 4.12.14-10.194.1 | 4.12.14-10.194.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-azure | before 4.12.14-16.194.1 | 4.12.14-16.194.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-source | before 4.12.14-122.222.1 | 4.12.14-122.222.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-source-azure | before 4.12.14-16.194.1 | 4.12.14-16.194.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-syms | before 4.12.14-122.222.1 | 4.12.14-122.222.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-syms-azure | before 4.12.14-16.194.1 | 4.12.14-16.194.1 |
| SUSE:Linux Enterprise Software Development Kit 12 SP5 | kernel-docs | before 4.12.14-122.222.1 | 4.12.14-122.222.1 |
| SUSE:Linux Enterprise Software Development Kit 12 SP5 | kernel-obs-build | before 4.12.14-122.222.1 | 4.12.14-122.222.1 |
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-2021-47142Mar 25, 2024 · drm/amdgpu: Fix a use-after-free22Monitor
- ← EarlierCVE-2021-47143Mar 25, 2024 · net/smc: remove device from smcd_dev_list after failed device_add()22Monitor
- Later →CVE-2021-47146Mar 25, 2024 · mld: fix panic in mld_newpack()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 / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 0eaf383c6a4a83c09f60fd07a1bea9f1a9181611 | Vendor (CNA) |
| Linux Linux | 0ed102453aa1cd12fefde8f6b60b9519b0b1f003 | Vendor (CNA) |
| Linux Linux | 6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9fa | Vendor (CNA) |
| Linux Linux | 76bfd8ac20bebeae599452a03dfc5724c0475dcf | Vendor (CNA) |
| Linux Linux | 7e13db503918820e6333811cdc6f151dcea5090a | Vendor (CNA) |
| Linux Linux | 91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96d | Vendor (CNA) |
| Linux Linux | b545442133580dcb2f2496133bf850824d41255c | Vendor (CNA) |
| Linux Linux | e934c4ee17b33bafb0444f2f9766cda7166d3c40 | Vendor (CNA) |
| debian:linux | 5.14.6-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-azure | 4.12.14-16.194.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-default | 4.12.14-122.222.1 · SUSE:Linux Enterprise High Availability Extension 12 SP5 | Package registry (OSV) |
| suse:kernel-docs | 4.12.14-122.222.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-obs-build | 4.12.14-122.222.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-rt | 4.12.14-10.194.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-rt_debug | 4.12.14-10.194.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-source | 4.12.14-122.222.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-azure | 4.12.14-16.194.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-rt | 4.12.14-10.194.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-syms | 4.12.14-122.222.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-syms-rt | 4.12.14-10.194.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kgraft-patch-SLE12-SP5_Update_58 | 1-8.3.1 · SUSE:Linux Enterprise Live Patching 12 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-24-0230 · Mar 26, 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)
—
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✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/0ed102453aa1cd12fefde8f6b60b9519b0b1f003
- git.kernel.org/stable/c/6eccfb28f8dca70c9b1b3bb3194ca54cbe73a9fa
- git.kernel.org/stable/c/76bfd8ac20bebeae599452a03dfc5724c0475dcf
- git.kernel.org/stable/c/7e13db503918820e6333811cdc6f151dcea5090a
- git.kernel.org/stable/c/91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96d
- git.kernel.org/stable/c/b545442133580dcb2f2496133bf850824d41255c
- git.kernel.org/stable/c/e934c4ee17b33bafb0444f2f9766cda7166d3c40
Vendor advisories and official records. Exploit/PoC links are deliberately left out.