CVE-2026-23454

Description

In the Linux kernel, the following vulnerability has been resolved: net: mana: fix use-after-free in mana_hwc_destroy_channel() by reordering teardown A potential race condition exists in mana_hwc_destroy_channel() where hwc->caller_ctx is freed before the HWC's Completion Queue (CQ) and Event Queue (EQ) are destroyed. This allows an in-flight CQ interrupt handler to dereference freed memory, leading to a use-after-free or NULL pointer dereference in mana_hwc_handle_resp(). mana_smc_teardown_hwc() signals the hardware to stop but does not synchronize against IRQ handlers already executing on other CPUs. The IRQ synchronization only happens in mana_hwc_destroy_cq() via mana_gd_destroy_eq() -> mana_gd_deregister_irq(). Since this runs after kfree(hwc->caller_ctx), a concurrent mana_hwc_rx_event_handler() can dereference freed caller_ctx (and rxq->msg_buf) in mana_hwc_handle_resp(). Fix this by reordering teardown to reverse-of-creation order: destroy the TX/RX work queues and CQ/EQ before freeing hwc->caller_ctx. This ensures all in-flight interrupt handlers complete before the memory they access is freed.

References

• https://git.kernel.org/stable/c/05d345719d85b927cba74afac4d5322de3aa4256
• https://git.kernel.org/stable/c/249e905571583a434d4ea8d6f92ccc0eef337115
• https://git.kernel.org/stable/c/2b001901f689021acd7bf2dceed74a1bdcaaa1f9
• https://git.kernel.org/stable/c/afdb1533eb9c05432aeb793a7280fa827c502f5c
• https://git.kernel.org/stable/c/e23bf444512cb85d76012080a76cd1f9e967448e