Bug 2451256 (CVE-2026-23362)

Summary: CVE-2026-23362 kernel: can: bcm: fix locking for bcm_op runtime updates
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Controller Area Network (CAN) Broadcast Manager (BCM) module. When the RX_RTR_FRAME flag is set and a specific Remote Transmission Request (RTR) frame is received, the bcm_tx_lock was not properly initialized in the bcm_rx_setup() function. This missing initialization of the lock could lead to a race condition, potentially allowing a local attacker to cause a Denial of Service (DoS) by triggering system instability.
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Description OSIDB Bzimport 2026-03-25 11:07:26 UTC
In the Linux kernel, the following vulnerability has been resolved:

can: bcm: fix locking for bcm_op runtime updates

Commit c2aba69d0c36 ("can: bcm: add locking for bcm_op runtime updates")
added a locking for some variables that can be modified at runtime when
updating the sending bcm_op with a new TX_SETUP command in bcm_tx_setup().

Usually the RX_SETUP only handles and filters incoming traffic with one
exception: When the RX_RTR_FRAME flag is set a predefined CAN frame is
sent when a specific RTR frame is received. Therefore the rx bcm_op uses
bcm_can_tx() which uses the bcm_tx_lock that was only initialized in
bcm_tx_setup(). Add the missing spin_lock_init() when allocating the
bcm_op in bcm_rx_setup() to handle the RTR case properly.