CVE-2021-47387: cpufreq: schedutil: Use kobject release() method to free sugov_tunables
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 30d57cf2c4116ca6d34ecd1cac94ad84f8bc446c, 463c46705f321201090b69c4ad5da0cd2ce614c9, 67c98e023135ff81b8d52998a6fdb8ca0c518d82.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 30d57cf2c4116ca6d34ecd1cac94ad84f8bc446c, 463c46705f321201090b69c4ad5da0cd2ce614c9, 67c98e023135ff81b8d52998a6fdb8ca0c518d82 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: cpufreq: schedutil: Use kobject release() method to free sugov_tunables The struct sugov_tunables is protected by the kobject, so we can't free it directly. Otherwise we would get a call trace like this: ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30 WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100 Modules linked in: CPU: 3 PID: 720 Comm: a.sh Tainted: G W 5.14.0-rc1-next-20210715-yocto-standard+ #507 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--) pc : debug_print_object+0xb8/0x100 lr : debug_print_object+0xb8/0x100 sp : ffff80001ecaf910 x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80 x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000 x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20 x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010 x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365 x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69 x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0 x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001 x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000 x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000 Call trace: debug_print_object+0xb8/0x100 __debug_check_no_obj_freed+0x1c0/0x230 debug_check_no_obj_freed+0x20/0x88 slab_free_freelist_hook+0x154/0x1c8 kfree+0x114/0x5d0 sugov_exit+0xbc/0xc0 cpufreq_exit_governor+0x44/0x90 cpufreq_set_policy+0x268/0x4a8 store_scaling_governor+0xe0/0x128 store+0xc0/0xf0 sysfs_kf_write+0x54/0x80 kernfs_fop_write_iter+0x128/0x1c0 new_sync_write+0xf0/0x190 vfs_write+0x2d4/0x478 ksys_write+0x74/0x100 __arm64_sys_write+0x24/0x30 invoke_syscall.constprop.0+0x54/0xe0 do_el0_svc+0x64/0x158 el0_svc+0x2c/0xb0 el0t_64_sync_handler+0xb0/0xb8 el0t_64_sync+0x198/0x19c irq event stamp: 5518 hardirqs last enabled at (5517): [<ffff8000100cbd7c>] console_unlock+0x554/0x6c8 hardirqs last disabled at (5518): [<ffff800010fc0638>] el1_dbg+0x28/0xa0 softirqs last enabled at (5504): [<ffff8000100106e0>] __do_softirq+0x4d0/0x6c0 softirqs last disabled at (5483): [<ffff800010049548>] irq_exit+0x1b0/0x1b8 So split the original sugov_tunables_free() into two functions, sugov_clear_global_tunables() is just used to clear the global_tunables and the new sugov_tunables_free() is used as kobj_type::release to release the sugov_tunables safely.
- Published
- May 21, 2024
- Updated
- Jun 17, 2026
- EPSS
- 0.2% · 16th percentile
- CWE
- CWE-763
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 kernel4.7 and later · before 4.9.285
- linux linux kernel4.10 and later · before 4.14.249
- linux linux kernel4.15 and later · before 4.19.209
- linux linux kernel4.20 and later · before 5.4.151
- linux linux kernel5.5 and later · before 5.10.71
- linux linux kernel5.11 and later · before 5.14.10
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
- 4.7affected
- 9bdcb44e391da5c41b98573bf0305a0e0b1c9569 and later · before cb4a53ba37532c861a5f3f22803391018a41849aaffected · git
- 9bdcb44e391da5c41b98573bf0305a0e0b1c9569 and later · before 463c46705f321201090b69c4ad5da0cd2ce614c9affected · git
- 9bdcb44e391da5c41b98573bf0305a0e0b1c9569 and later · before 30d57cf2c4116ca6d34ecd1cac94ad84f8bc446caffected · git
- 9bdcb44e391da5c41b98573bf0305a0e0b1c9569 and later · before 67c98e023135ff81b8d52998a6fdb8ca0c518d82affected · git
- 9bdcb44e391da5c41b98573bf0305a0e0b1c9569 and later · before a7d4fc84404d45d72f4490417e8cc3efa4af93f1affected · git
- 9bdcb44e391da5c41b98573bf0305a0e0b1c9569 and later · before 8d62aec52a8c5b1d25a2364b243fcc5098a2ede9affected · git
- 9bdcb44e391da5c41b98573bf0305a0e0b1c9569 and later · before e5c6b312ce3cc97e90ea159446e6bfa06645364daffected · git
- before 4.7not affected · semver
- 4.9.285 and later · up to and including 4.9.*not 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 5.14.12-1 | 5.14.12-1 |
| SUSE:Linux Enterprise High Availability Extension 12 SP5 | kernel-default | before 4.12.14-122.231.1 | 4.12.14-122.231.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_61 | before 1-8.3.1 | 1-8.3.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-rt | before 4.12.14-10.203.1 | 4.12.14-10.203.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-rt_debug | before 4.12.14-10.203.1 | 4.12.14-10.203.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-source-rt | before 4.12.14-10.203.1 | 4.12.14-10.203.1 |
| SUSE:Linux Enterprise Real Time 12 SP5 | kernel-syms-rt | before 4.12.14-10.203.1 | 4.12.14-10.203.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-azure | before 4.12.14-16.200.1 | 4.12.14-16.200.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-source | before 4.12.14-122.231.1 | 4.12.14-122.231.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-source-azure | before 4.12.14-16.200.1 | 4.12.14-16.200.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-syms | before 4.12.14-122.231.1 | 4.12.14-122.231.1 |
| SUSE:Linux Enterprise Server 12 SP5 | kernel-syms-azure | before 4.12.14-16.200.1 | 4.12.14-16.200.1 |
| SUSE:Linux Enterprise Software Development Kit 12 SP5 | kernel-docs | before 4.12.14-122.231.1 | 4.12.14-122.231.1 |
| SUSE:Linux Enterprise Software Development Kit 12 SP5 | kernel-obs-build | before 4.12.14-122.231.1 | 4.12.14-122.231.1 |
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-2021-47385May 21, 2024 · hwmon: (w83792d) Fix NULL pointer dereference by removing unnecessary structure field22Monitor
- ← EarlierCVE-2021-47386May 21, 2024 · hwmon: (w83791d) Fix NULL pointer dereference by removing unnecessary structure field31Monitor
- Later →CVE-2021-47388May 21, 2024 · mac80211: fix use-after-free in CCMP/GCMP RX31Monitor
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 | 30d57cf2c4116ca6d34ecd1cac94ad84f8bc446c | Vendor (CNA) |
| Linux Linux | 463c46705f321201090b69c4ad5da0cd2ce614c9 | Vendor (CNA) |
| Linux Linux | 67c98e023135ff81b8d52998a6fdb8ca0c518d82 | Vendor (CNA) |
| Linux Linux | 8d62aec52a8c5b1d25a2364b243fcc5098a2ede9 | Vendor (CNA) |
| Linux Linux | a7d4fc84404d45d72f4490417e8cc3efa4af93f1 | Vendor (CNA) |
| Linux Linux | cb4a53ba37532c861a5f3f22803391018a41849a | Vendor (CNA) |
| Linux Linux | e5c6b312ce3cc97e90ea159446e6bfa06645364d | Vendor (CNA) |
| debian:linux | 5.14.12-1 · Debian:12 | Package registry (OSV) |
| suse:kernel-azure | 4.12.14-16.200.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-default | 4.12.14-122.231.1 · SUSE:Linux Enterprise High Availability Extension 12 SP5 | Package registry (OSV) |
| suse:kernel-docs | 4.12.14-122.231.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-obs-build | 4.12.14-122.231.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
| suse:kernel-rt | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-rt_debug | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-source | 4.12.14-122.231.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-azure | 4.12.14-16.200.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-source-rt | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kernel-syms | 4.12.14-122.231.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:kernel-syms-rt | 4.12.14-10.203.1 · SUSE:Linux Enterprise Real Time 12 SP5 | Package registry (OSV) |
| suse:kgraft-patch-SLE12-SP5_Update_61 | 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.
- CVE-2021-4708778 days aparttee: optee: Fix incorrect page free bug31Monitor
- CVE-2022-48425430 days apartIn the Linux kernel through 6.2.7, fs/ntfs3/inode.c has an invalid kfree because it does not validate MFT flags before replaying logs.31Monitor
- CVE-2022-4696496 days apartThere exists a use-after-free vulnerability in the Linux kernel through io_uring and the IORING_OP_SPLICE operation.31Monitor
- CVE-2024-4213270 days apartbluetooth/hci: disallow setting handle bigger than HCI_CONN_HANDLE_MAX28Monitor
- CVE-2021-472210 days apartmm/slub: actually fix freelist pointer vs redzoning22Monitor
- CVE-2024-358324 days apartbcachefs: kvfree bch_fs::snapshots in bch2_fs_snapshots_exit22Monitor
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-24-0519 · May 22, 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-763 · Release of Invalid Pointer or ReferenceCVSS 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 (6 more)Show less
- git.kernel.org/stable/c/463c46705f321201090b69c4ad5da0cd2ce614c9
- git.kernel.org/stable/c/67c98e023135ff81b8d52998a6fdb8ca0c518d82
- git.kernel.org/stable/c/8d62aec52a8c5b1d25a2364b243fcc5098a2ede9
- git.kernel.org/stable/c/a7d4fc84404d45d72f4490417e8cc3efa4af93f1
- git.kernel.org/stable/c/cb4a53ba37532c861a5f3f22803391018a41849a
- git.kernel.org/stable/c/e5c6b312ce3cc97e90ea159446e6bfa06645364d
Vendor advisories and official records. Exploit/PoC links are deliberately left out.