CVE-2026-99211

A flaw was found in Red Hat Enterprise Linux 9 kernel builds. An incomplete backport of the CVE-2026-46099 fix in RHEL 9.6 through 9.10 left a local_bh imbalance in seg6_input_core(), where the drop path returns with bottom halves still disabled. This can lead to softirq starvation and denial of service on systems with SRv6 tunnels configured. Upstream and RHEL 10 are not affected.

In the Linux kernel, the Hyper-V (hv) driver incorrectly forces the VMBus connection state to DISCONNECTED before calling vmbus_disconnect(). As a result, vmbus_initiate_unload() does not unload the connection because it only acts when the state is CONNECTED, so the Hyper-V host may continue sending messages or posting VMBus interrupts.

In the Linux kernel power supply subsystem, a use-after-free vulnerability exists. If a power supply is unregistered while its external_power_changed() callback is still running, the driver may free data that the callback is still accessing, leading to a kernel crash (NULL pointer dereference).

In the Linux kernel, the drm/vc4 HDMI driver has an ordering issue with Packet RAM enabling. When audio is triggered by the HPD handler before video is restored, vc4_hdmi_write_infoframe() may attempt to store an infoframe while Packet RAM is disabled, causing a kernel warning (splat). The fix moves Packet RAM enable/disable into the Runtime PM hooks.

In the Linux kernel vsock subsystem, the TCP_ESTABLISHED to TCP_CLOSING transition on OP_RST can race with the connect loop. Resetting a socket still present in connected_table can lead to memory corruption, including a double list add and a kernel BUG.

In the Linux kernel net/rds module, rds_rdma_cm_event_handler_cmn() returns the result of rdma_resolve_route() directly to rdma_cm on RDMA_CM_EVENT_ADDR_RESOLVED. A synchronous failure causes the id ic->i_cm_id to be destroyed while RDS still owns it, leading to use of a freed id during connection shutdown.

In the Linux kernel accel/rocket driver, rocket_probe() stores the return value of rocket_device_init() in the file-scoped rdev pointer before checking whether it is an error pointer. On failure rdev remains an ERR_PTR, and a later probe can skip initialization and dereference the error pointer when reading rdev->num_cores.

In the Linux kernel drm/xe driver, xe_evict_flags() reads tbo->resource->mem_type, but a BO can reach eviction with no ttm.resource, e.g. an imported dma-buf whose resource was freed during teardown. This causes a NULL pointer dereference and a kernel fault.

In the Linux kernel drm/xe/oa driver, ttm_bo_type_kernel BOs are not guaranteed to be zeroed on allocation and may contain data from previously freed pages. Since the OA buffer is mmap'able by userspace, this can expose stale kernel memory contents.

In the Linux kernel's scsi: target subsystem, target_do_delayed_work() acquired delayed_cmd_lock with a plain spin_lock() without disabling interrupts, while all other acquisition sites use spin_lock_irqsave(). Since commands can now complete in interrupt context (complete_type=1 with direct_compl_supp), this can cause a deadlock when a completion arrives on the same CPU where the work item holds the lock.