Linux Kernel up to 7.2-rc4 mt7921 mt7921_mac_tx_free null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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7.2$0-$5k1.07+

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.147/6.12.100/6.18.41/7.1.5/7.2-rc4 and classified as critical. This affects the function mt7921_mac_tx_free of the component mt7921. Executing a manipulation can lead to null pointer dereference. This vulnerability appears as CVE-2026-68194. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.147/6.12.100/6.18.41/7.1.5/7.2-rc4. It has been declared as critical. This vulnerability affects the function mt7921_mac_tx_free of the component mt7921. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7921: drop TXRX_NOTIFY on non-mmio buses PKT_TYPE_TXRX_NOTIFY is an mmio-only event, but mt7921_rx_check() and mt7921_queue_rx_skb() dispatch it to mt7921_mac_tx_free() on every bus. mt7921_mac_tx_free() cleans the DMA tx queues with mt76_queue_tx_cleanup(), which calls queue_ops->tx_cleanup(). Only the mmio queue ops implement that callback; on USB and SDIO it is NULL, so a TXRX_NOTIFY there calls a NULL pointer in the RX worker: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:0x0 Call Trace: mt7921_mac_tx_free+0x64/0x310 [mt7921_common] mt7921_rx_check+0x5f/0xf0 [mt7921_common] mt76u_rx_worker+0x1b9/0x620 [mt76_usb] Drop the event on non-mmio buses via mt76_is_mmio(), as in commit 5683e1488aa9 ("wifi: mt76: connac: do not check WED status for non-mmio devices").

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-68194 since 07/30/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. 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 08/10/2026).

Upgrading to version 6.6.148, 6.12.101, 6.18.42, 7.1.6 or 7.2-rc5 eliminates this vulnerability. Applying the patch ef2ee5f820c3ef87643b51e960c20b4a14d8336b/ecf995b828191829ba4a87169bccabcbeb5c9c32/263816e92e8d66c81c98ccab2b5d2191ed08ec71/24475d2ddc8d8dfd82f4d2be0d951401f86911a6/da4082e91acabc1498611ed8ccc53f0610baefc6 is able to eliminate this problem.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.148/6.12.101/6.18.42/7.1.6/7.2-rc5
Patch: ef2ee5f820c3ef87643b51e960c20b4a14d8336b/ecf995b828191829ba4a87169bccabcbeb5c9c32/263816e92e8d66c81c98ccab2b5d2191ed08ec71/24475d2ddc8d8dfd82f4d2be0d951401f86911a6/da4082e91acabc1498611ed8ccc53f0610baefc6

Timelineinfo

07/30/2026 CVE reserved
08/10/2026 +11 days Advisory disclosed
08/10/2026 +0 days VulDB entry created
08/10/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-68194 (🔒)
GCVE (CVE): GCVE-0-2026-68194
GCVE (VulDB): GCVE-100-387538

Entryinfo

Created: 08/10/2026 15:55
Changes: 08/10/2026 15:55 (59)
Complete: 🔍
Cache ID: 216::103

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