Linux Kernel up to 6.18.45/7.1.10 Futex futex_pivot_pending race condition

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 5.3 | $0-$5k | 0.00- |
Summary
A vulnerability marked as critical has been reported in Linux Kernel up to 6.18.45/7.1.10. Affected by this issue is the function futex_pivot_pending of the component Futex. The manipulation leads to race condition.
This vulnerability is uniquely identified as CVE-2026-80776. Local access is required to approach this attack. No exploit exists.
Details
A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.45/7.1.10. This issue affects the function futex_pivot_pending of the component Futex. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is availability. The summary by CVE is:
In the Linux kernel, the following vulnerability has been resolved: futex: Fix race in futex_pivot_pending() during private hash resize A task performing a custom private hash resize can remain blocked in uninterruptible sleep indefinitely. The hung-task detector reports: INFO: task futex-resizer:314 blocked for more than 10 seconds. task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311 Call Trace: __schedule+0x521/0xf30 schedule+0x22/0xa0 futex_hash_allocate+0x3db/0x490 __do_sys_prctl+0x6f5/0xbd0 do_syscall_64+0xf9/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f Kernel panic - not syncing: hung_task: blocked tasks futex_pivot_pending() allows the resize request to continue when either no replacement hash is pending (hash_new == NULL) or the current hash reference count has reached zero. After the final-reference wake, another futex task can complete the pivot between the two observations: T1 T2 futex_hash_allocate() wait_var_event(mm, ...) futex_pivot_pending(mm) hash_new != NULL futex_hash() futex_ref_get(old) -> false futex_pivot_hash(mm) hash_new = NULL __futex_pivot_hash(mm, new) rcu_assign_pointer(hash, new) fph = rcu_dereference(hash) /* new */ futex_ref_is_dead(fph) -> false schedule() The pivot changes the state from hash_new != NULL with a dead current hash to hash_new == NULL with a live current hash. Because futex_pivot_pending() reads hash_new and hash without serialization, the resize task can observe hash_new in the pre-pivot state and hash in the post-pivot state, causing futex_pivot_pending() to return false even though the pivot has completed. The task then goes to sleep after the wakeup has already been consumed. Serialize state reads in futex_pivot_pending() using futex_mm_phash::lock. This guarantees that futex_pivot_pending() observes hash_new and hash atomically, eliminating the race condition.
It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-80776 since 08/26/2026. The exploitation is known to be easy. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit.
Upgrading to version 6.18.46 or 7.1.11 eliminates this vulnerability. Applying the patch 4a7e941ca29a608c6244cbd028d3599ecaef7207/19b4be0717fa83265d66aea836b7022d898422cf/8e7ff730dd96519a333d1570edf1c3fabb6d3629 is able to eliminate this problem.
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Product
Type
Vendor
Name
Version
- 6.18.0
- 6.18.1
- 6.18.2
- 6.18.3
- 6.18.4
- 6.18.5
- 6.18.6
- 6.18.7
- 6.18.8
- 6.18.9
- 6.18.10
- 6.18.11
- 6.18.12
- 6.18.13
- 6.18.14
- 6.18.15
- 6.18.16
- 6.18.17
- 6.18.18
- 6.18.19
- 6.18.20
- 6.18.21
- 6.18.22
- 6.18.23
- 6.18.24
- 6.18.25
- 6.18.26
- 6.18.27
- 6.18.28
- 6.18.29
- 6.18.30
- 6.18.31
- 6.18.32
- 6.18.33
- 6.18.34
- 6.18.35
- 6.18.36
- 6.18.37
- 6.18.38
- 6.18.39
- 6.18.40
- 6.18.41
- 6.18.42
- 6.18.43
- 6.18.44
- 6.18.45
- 7.1.0
- 7.1.1
- 7.1.2
- 7.1.3
- 7.1.4
- 7.1.5
- 7.1.6
- 7.1.7
- 7.1.8
- 7.1.9
- 7.1.10
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 5.5VulDB Meta Temp Score: 5.3
VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Race conditionCWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒
Physical: Partially
Local: Yes
Remote: No
Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒
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Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 6.18.46/7.1.11
Patch: 4a7e941ca29a608c6244cbd028d3599ecaef7207/19b4be0717fa83265d66aea836b7022d898422cf/8e7ff730dd96519a333d1570edf1c3fabb6d3629
Timeline
08/26/2026 CVE reserved09/04/2026 Advisory disclosed
09/04/2026 VulDB entry created
09/04/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-80776 (🔒)
GCVE (CVE): GCVE-0-2026-80776
GCVE (VulDB): GCVE-100-398927
Entry
Created: 09/04/2026 18:21Changes: 09/04/2026 18:21 (59)
Complete: 🔍
Cache ID: 216::103
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