CVE-2026-74691 — net: thunderbolt: Tear down DMA paths before stopping the rings

Affected: Linux

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

net: thunderbolt: Tear down DMA paths before stopping the rings

tbnet_tear_down() stops both rings and frees their frame buffers before calling tb_xdomain_disable_paths(). tb_ring_stop() zeroes the ring's descriptor base and tbnet_free_buffers() unmaps and frees the pages the frames sit in, so by the time __tb_path_deactivate_hop() polls the hop's 'pending' bit, anything still in flight has nowhere to drain to.

The teardown sequence has been in this order since the driver was added. The setup path has not: commit ff7cd07f3064 ("net: thunderbolt: Enable DMA paths only after rings are enabled") moved the path enable to the end of tbnet_connected_work() and documented why:

/* Both logins successful so enable the rings, high-speed DMA * paths and start the network device queue. * * Note we enable the DMA paths last to make sure we have primed * the Rx ring before any incoming packets are allowed to * arrive. */

Teardown was never updated to match, so the rings and the paths now come down in the same order they go up instead of in reverse.

On an ASMedia ASM4242 host router the 'pending' bit then never clears: every teardown burns the full 500 ms timeout and __tb_path_deactivate_hop() returns -ETIMEDOUT. Raising the timeout to 5 s does not help, so the hop is not slow to drain, it never drains at all.

The failure is invisible above the thunderbolt core. __tb_path_deactivate_hops() is void and…

USN-8875-1 — linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-azure, linux-azure-5.15, linux-azure-fde-5.15, linux-azure-fips…

Affected: Ubuntu:Pro:20.04:LTS: linux-aws-5.15, Ubuntu:Pro:20.04:LTS: linux-azure-5.15, Ubuntu:Pro:20.04:LTS: linux-azure-fde-5.15, Ubuntu:Pro:20.04:LTS: linux-hwe-5.15, Ubuntu:Pro:20.04:LTS: linux-ibm-5.15, Ubuntu:Pro:20.04:LTS: linux-intel-iotg-5.15, Ubuntu:Pro:20.04:LTS: linux-lowlatency-hwe-5.15, Ubuntu:22.04:LTS: linux, Ubuntu:22.04:LTS: linux-aws, Ubuntu:22.04:LTS: linux-azure and 13 more

It was discovered that the i.MX clock driver in the Linux kernel did not properly handle certain memory allocation failure conditions, leading to a null pointer dereference vulnerability. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2022-3114)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - User-space API (UAPI); - ARM32 architecture; - ARM64 architecture; - MIPS architecture; - PowerPC architecture; - RISC-V architecture; - User-Mode Linux (UML); - x86 architecture; - Block layer subsystem; - Cryptographic API; - ACPI drivers; - Android drivers; - Serial ATA and Parallel ATA drivers; - Drivers core; - DRBD Distributed Replicated Block Device drivers; - Rados block device (RBD) driver; - Bluetooth drivers; - Cdrom driver; - Character device driver; - Hardware random number generator core; - TPM device driver; - Data acquisition framework and drivers; - CPU frequency scaling framework; - Hardware crypto device drivers; - DAX dirext access to differentiated memory framework; - DMA engine subsystem; - FireWire subsystem; - Arm Firmware Framework for ARMv8-A(FFA); - ARM SCMI message protocol; - Intel Stratix 10 firmware drivers; - FPGA Framework; - GPIO subsystem; - GPU drivers; - HID subsystem; - Hardware monitoring drivers; - In…

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CVE-2026-74691 — net: thunderbolt: Tear down DMA paths before stopping the rings

USN-8875-1 — linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-azure, linux-azure-5.15, linux-azure-fde-5.15, linux-azure-fips…