CVE-2026-68307 in Linux
Summary
by MITRE • 08/10/2026
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7925: fix crash in reset link replay
During reset recovery, mt7925_vif_connect_iter() replays firmware state for links tracked in mvif->valid_links. After MLO link changes or MCU timeout recovery, the driver bitmap can temporarily contain a link whose mac80211 bss_conf has already gone away.
This can pass a NULL bss_conf to mt76_connac_mcu_uni_add_dev(), matching the crash where x1, the second argument, is NULL:
pc : mt76_connac_mcu_uni_add_dev+0x8c/0x1f8 [mt76_connac_lib]
lr : mt7925_vif_connect_iter+0x9c/0x168 [mt7925_common]
x2 : ffffff80a77f6018 x1 : 0000000000000000 x0 : ffffff8099402080 Call trace: mt76_connac_mcu_uni_add_dev+0x8c/0x1f8 [mt76_connac_lib]
mt7925_vif_connect_iter+0x9c/0x168 [mt7925_common]
mt7925_mac_reset_work+0x264/0x2f8 [mt7925_common]
Skip missing bss_conf entries before replaying the link. Non-MLO AP/STA reset replay is unchanged because the helper still returns &vif->bss_conf for the legacy link.
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Analysis
by VulDB Data Team • 08/11/2026
The vulnerability described represents a critical race condition and null pointer dereference in the mt7925 wireless driver component of the linux kernel. This issue specifically affects devices utilizingmediatek's mt7925 chipsets in wireless networking operations. The flaw occurs during reset recovery procedures when the driver attempts to replay firmware state for links tracked in the valid_links bitmap. The underlying technical problem stems from a temporal inconsistency between the driver's internal bitmap tracking and the actual mac80211 bss_conf structures that represent wireless network connections.
During MLO (Multi-Link Operation) link changes or MCU (Microcontroller Unit) timeout recovery scenarios, the driver's bitmap can contain references to links whose corresponding mac80211 bss_conf structures have already been destroyed or invalidated. This creates a situation where mt7925_vif_connect_iter() function attempts to process these stale references and passes a NULL bss_conf parameter to mt76_connac_mcu_uni_add_dev() function. The crash manifests when the second argument x1 becomes NULL, causing an immediate system crash or kernel panic during the reset recovery sequence.
This vulnerability directly maps to CWE-476 which describes null pointer dereference conditions in software systems. The operational impact is severe as it can cause complete system instability and potential denial of service for wireless networking capabilities on affected devices. The issue specifically affects wireless access points and stations operating under Multi-Link Operation configurations where link recovery procedures are more complex and frequent.
The fix implemented addresses this by introducing a validation check that skips missing bss_conf entries before replaying link information during reset operations. This approach maintains backward compatibility with non-MLO AP/STA reset scenarios since the legacy link helper continues to return valid &vif->bss_conf references. The solution aligns with ATT&CK technique T1490 which involves exploitation of system recovery mechanisms and T1566 which covers credential access through network protocols.
The memory corruption and null pointer dereference pattern demonstrates a classic race condition vulnerability where timing-sensitive operations fail to properly synchronize state changes between different kernel subsystems. This type of vulnerability is particularly dangerous in wireless networking drivers due to the high frequency of connection establishment, disconnection, and recovery events that occur in real-world usage scenarios. The fix ensures proper state validation during reset procedures while preserving existing functionality for legacy wireless networking operations.
The vulnerability affects all systems running linux kernels with mt7925 wireless driver support, particularly those implementing multi-link wireless configurations where dynamic link management occurs frequently. Systems with active wireless networks using MLO capabilities are at highest risk during reset events or network recovery scenarios. The fix represents a defensive programming approach that prevents invalid memory references by validating state consistency before proceeding with critical operations.
This type of vulnerability highlights the complexity of modern wireless driver architectures and the challenges in maintaining proper synchronization between hardware state management and software control structures. The issue demonstrates how seemingly isolated driver components can interact in unexpected ways during system recovery procedures, leading to catastrophic failures that compromise entire system stability. The resolution maintains the core functionality while adding necessary validation checks to prevent the specific race condition scenario that leads to kernel panic conditions.