Linux Kernel up to 7.1.7 isotp isotp_sendmsg txfrtimer/wait/tx_gen/tx_result/sk_err race condition

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.4	$0-$5k	0.82

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.1.7. It has been declared as very critical. Affected is the function isotp_sendmsg of the component isotp. The manipulation of the argument txfrtimer/wait/tx_gen/tx_result/sk_err results in race condition. This vulnerability is known as CVE-2026-80889. Attacking locally is a requirement. No exploit is available.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.1.7. Affected is the function isotp_sendmsg of the component isotp. The manipulation of the argument txfrtimer/wait/tx_gen/tx_result/sk_err with an unknown input leads to a race condition vulnerability. CWE is classifying the issue as 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. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: can: isotp: fix timer drain order, wakeup handling and tx_gen ordering This patch is a follow-up to commit cf070fe33bfb ("can: isotp: serialize TX state transitions under so->rx_lock") which addresses following sashiko-bot findings: - isotp_sendmsg(): drain so->txfrtimer first so a stale callback can't re-arm echotimer after the claim - isotp_release(): wake so->wait after forcing ISOTP_SHUTDOWN so a sleeping sendmsg() claim isn't stranded - isotp_sendmsg(): have both wait_event_interruptible() calls in isotp_sendmsg() also wake on ISOTP_SHUTDOWN and do not return claim to IDLE to avoid corrupting a concurrent isotp_release() process. - isotp_sendmsg(): handle potential claim of a new transfer when the wait_event_interruptible() call returns in CAN_ISOTP_WAIT_TX_DONE mode. Don't touch timers and states of the new transfer if a new thread incremented so->tx_gen before getting the lock at err_event_drop. - isotp_sendmsg(): handle a stuck can_send() and omit timer and state changes if a new transfer was claimed. wait_tx_done() returns the error recorded in so->tx_result[], tagged with the caller's own generation. - isotp_tx_timeout(): on a claimed timeout, record the ECOMM error for the timed-out transfer's own generation in so->tx_result[]; sk->sk_err is raised unconditionally, same as every other error path here. - isotp_tx_gen_done()/isotp_tx_timeout(): always read tx.state (acquire) before tx_gen - the reverse order let a weakly ordered CPU pair a fresh tx.state with a stale tx_gen/tx_result slot. - isotp_sendmsg(): wait_tx_done: drain sk_err via sock_error() once we have read the result from so->tx_result[], so an already-reported error doesn't stay latched for a later poll()/SO_ERROR. Also align the remaining lock-free so->tx.state/rx.state/cfecho accesses and use skb->hash as unique loopback echo frame indicator.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-80889 since 08/26/2026. The exploitability is told to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/04/2026).

Upgrading to version 5.10.267, 5.15.218, 6.1.185, 6.6.151, 6.12.103, 6.18.44 or 7.1.8 eliminates this vulnerability. Applying the patch 8acab9fc66d6f426c36968c91a979f70784945a7/af7e25c649ed68cbad07f8185af0f31b892cbf29/2753722612d8824d3910096f93059f669009b0f0/bf5c4a8b24acb12739ebb9aea5510b007e4f5239/deca7746b57d982cd4f0301f4443f56780c4a048/10be509fa8fd95d1e47d40d1f68b0b26dfe9d572/35c62ac98d06669aa3f0f38b7829eaca929a611e/050f010f920da17c1044a4f174766ad553e770b6 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.266
• 5.15.217
• 6.1.184
• 6.6.150
• 6.12.102
• 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
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3
• 7.1.4
• 7.1.5
• 7.1.6
• 7.1.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.267/5.15.218/6.1.185/6.6.151/6.12.103/6.18.44/7.1.8
Patch: 8acab9fc66d6f426c36968c91a979f70784945a7/af7e25c649ed68cbad07f8185af0f31b892cbf29/2753722612d8824d3910096f93059f669009b0f0/bf5c4a8b24acb12739ebb9aea5510b007e4f5239/deca7746b57d982cd4f0301f4443f56780c4a048/10be509fa8fd95d1e47d40d1f68b0b26dfe9d572/35c62ac98d06669aa3f0f38b7829eaca929a611e/050f010f920da17c1044a4f174766ad553e770b6

Timelineinfo

08/26/2026 CVE reserved
09/04/2026 +9 days Advisory disclosed
09/04/2026 +0 days VulDB entry created
09/04/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80889 (🔒)
GCVE (CVE): GCVE-0-2026-80889
GCVE (VulDB): GCVE-100-399090

Entryinfo

Created: 09/04/2026 19:33
Changes: 09/04/2026 19:33 (60)
Complete: 🔍
Cache ID: 216::103

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Discussion

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