Bug 2451265 (CVE-2026-23357)

Summary: CVE-2026-23357 kernel: can: mcp251x: fix deadlock in error path of mcp251x_open
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's mcp251x Controller Area Network (CAN) driver. A local attacker could trigger a deadlock condition within the `mcp251x_open()` function's error handling path. This occurs when the `free_irq()` function is called while the `mpc_lock` mutex is held and an interrupt simultaneously occurs, causing the interrupt handler to wait for the same lock. This can lead to a system hang, resulting in a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-03-25 11:07:52 UTC
In the Linux kernel, the following vulnerability has been resolved:

can: mcp251x: fix deadlock in error path of mcp251x_open

The mcp251x_open() function call free_irq() in its error path with the
mpc_lock mutex held. But if an interrupt already occurred the
interrupt handler will be waiting for the mpc_lock and free_irq() will
deadlock waiting for the handler to finish.

This issue is similar to the one fixed in commit 7dd9c26bd6cf ("can:
mcp251x: fix deadlock if an interrupt occurs during mcp251x_open") but
for the error path.

To solve this issue move the call to free_irq() after the lock is
released. Setting `priv->force_quit = 1` beforehand ensure that the IRQ
handler will exit right away once it acquired the lock.