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

vhost_vdpa: assign irq bypass producer token correctly

We used to call irq_bypass_unregister_producer() in
vhost_vdpa_setup_vq_irq() which is problematic as we don't know if the
token pointer is still valid or not.

Actually, we use the eventfd_ctx as the token so the life cycle of the
token should be bound to the VHOST_SET_VRING_CALL instead of
vhost_vdpa_setup_vq_irq() which could be called by set_status().

Fixing this by setting up irq bypass producer's token when handling
VHOST_SET_VRING_CALL and un-registering the producer before calling
vhost_vring_ioctl() to prevent a possible use after free as eventfd
could have been released in vhost_vring_ioctl(). And such registering
and unregistering will only be done if DRIVER_OK is set.

kernel.org https://git.kernel.org/stable/c/02e9e9366fefe461719da5d173385b6685f70319 [No types assigned]

kernel.org https://git.kernel.org/stable/c/0c170b1e918b9afac25e2bbd01eaa2bfc0ece8c0 [No types assigned]

kernel.org https://git.kernel.org/stable/c/7cf2fb51175cafe01df8c43fa15a06194a59c6e2 [No types assigned]

kernel.org https://git.kernel.org/stable/c/927a2580208e0f9b0b47b08f1c802b7233a7ba3c [No types assigned]

kernel.org https://git.kernel.org/stable/c/ca64edd7ae93402af2596a952e0d94d545e2b9c0 [No types assigned]

kernel.org https://git.kernel.org/stable/c/ec5f1b54ceb23475049ada6e7a43452cf4df88d1 [No types assigned]

kernel.org https://git.kernel.org/stable/c/fae9b1776f53aab93ab345bdbf653b991aed717d [No types assigned]