CVE-2026-46004

In the Linux kernel, the following vulnerability has been resolved:

ALSA: caiaq: Handle probe errors properly

The probe procedure of setup_card() in caiaq driver doesnt treat the error cases gracefully, e.g. the error from snd_card_register() calls snd_card_free() but continues. This would lead to a UAF for the further calls like snd_usb_caiaq_control_init(), as Berk suggested in another patch in the link below.

However, the problem is not only that; in general, this function drops the all error handlings (as its a void function) although its caller can propagate an error to snd_probe(), which eventually calls snd_card_free() as a proper error path. That said, we should treat each error case in setup_card(), and just return the error code promptly, which is then handled later as a fatal error in snd_probe().

This patch achieves it by changing the setup_card() to return an error code. Also, the superfluous snd_card_free() call is removed, too.

Note that card->private_free can be set still safely at returning an error. All called functions in card_free() have checks of the unassigned resources or NULL checks.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/09616e25f502080ba684fc7fcf959d1376ab756d
• https://git.kernel.org/stable/c/096dd8519cf2f768e9e14f224b627f7aaee1a9c5
• https://git.kernel.org/stable/c/28abd224db4a49560b452115bca3672a20e45b2f
• https://git.kernel.org/stable/c/6251e3e256337a30160ef59ab1580dde4d1acd28
• https://git.kernel.org/stable/c/b956e48371f2ff72b76be9a829800ecec963bd45
• https://git.kernel.org/stable/c/da938aa9fc7826901921dcea225948ab21a97e45
• https://git.kernel.org/stable/c/e59ecd4ee3a450db6cb4e4ecaa3efdd593f80056
• https://git.kernel.org/stable/c/f537e3ad69609f6924a4db6b4a7f6561f5288bdd