CVE-2026-74734
Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
26/08/2026
Última modificación:
26/08/2026
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
firewire: ohci: fix NULL pointer dereference in ar_context_release<br />
<br />
During the error handling path of the driver&#39;s probe function, a NULL<br />
pointer dereference can occur in ar_context_release().<br />
<br />
When pci_probe() fails early (e.g., if pcim_enable_device() or MMIO mapping<br />
fails), the devres cleanup mechanism invokes release_ohci(). This function<br />
unconditionally calls ar_context_release() to clean up the asynchronous<br />
receive contexts. However, if ar_context_init() was not yet called,<br />
ctx->ohci remains NULL (as the fw_ohci structure is zero-initialized by<br />
devres_alloc()).<br />
<br />
ar_context_release() immediately dereferences ctx->ohci to get the dev<br />
pointer before checking if the context was actually initialized, leading to<br />
a crash:<br />
<br />
Oops: general protection fault, probably for non-canonical address<br />
0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI<br />
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]<br />
RIP: 0010:ar_context_release+0x3f/0x380 drivers/firewire/ohci.c:543<br />
Call Trace:<br />
release_ohci+0x3f/0x60 drivers/firewire/ohci.c:3567<br />
release_nodes drivers/base/devres.c:546 [inline]<br />
devres_release_all+0x1a8/0x260 drivers/base/devres.c:576<br />
device_unbind_cleanup drivers/base/dd.c:597 [inline]<br />
really_probe+0x451/0xae0 drivers/base/dd.c:772<br />
<br />
To fix this, move the assignment of the dev pointer after the !ctx->buffer<br />
check. If ctx->buffer is NULL, it indicates that the context was never<br />
successfully initialized and there is nothing to release, safely avoiding<br />
the dereference of the uninitialized ctx->ohci pointer.



