CVE Catalog

CVE-2026-74734

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel's firewire: ohci driver, a NULL pointer dereference vulnerability was found in ar_context_release(). The issue occurs during the error handling path of the probe function when the context was not initialized, and the devres cleanup mechanism triggers release. An attacker could exploit this to cause a kernel crash (system panic).

Risk Assessment

The vulnerability can be exploited locally to cause a denial of service (DoS) by deliberately triggering an error during FireWire driver initialization. This requires access to FireWire hardware or the ability to force a failed driver load, potentially leading to system instability.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit that moves the dev pointer assignment after the ctx->buffer check). If updating is not possible, consider disabling the firewire-ohci module on systems where it is not required.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: firewire: ohci: fix NULL pointer dereference in ar_context_release During the error handling path of the driver's probe function, a NULL pointer dereference can occur in ar_context_release(). When pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping fails), the devres cleanup mechanism invokes release_ohci(). This function unconditionally calls ar_context_release() to clean up the asynchronous receive contexts. However, if ar_context_init() was not yet called, ctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by devres_alloc()). ar_context_release() immediately dereferences ctx->ohci to get the dev pointer before checking if the context was actually initialized, leading to a crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543 Call Trace: release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567 release_nodes drivers/base/devres.c:546 [inline] devres_release_all+0x1a8/0x260 drivers/base/devres.c:576 device_unbind_cleanup drivers/base/dd.c:597 [inline] really_probe+0x451/0xae0 drivers/base/dd.c:772 To fix this, move the assignment of the dev pointer after the !ctx->buffer check. If ctx->buffer is NULL, it indicates that the context was never successfully initialized and there is nothing to release, safely avoiding the dereference of the uninitialized ctx->ohci pointer.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS