{"id":"CVE-2026-98342","published":"2026-10-06T09:18:27.003","lastModified":"2026-10-06T09:18:27.003","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: wait for RCU readers before releasing dma_device\n\ndma_issue_pending_all() walks the dma_device_list with\nlist_for_each_entry_rcu() under rcu_read_lock(). dma_device_release()\nunlinks the device with list_del_rcu() and then calls\ndevice->device_release() (which in many drivers, such as plx_dma.c,\ndirectly calls kfree()).\n\nBecause there is no grace period between unlinking the device and\nfreeing it, concurrent RCU readers in dma_issue_pending_all() can\naccess the device after it has been freed.\n\nThe lockless walk originally relied on clients holding a dmaengine\nreference to pin the provider module, and therefore the device, for as\nlong as they might traverse the list. Commit 8ad342a86359 (\"dmaengine:\nAdd reference counting to dma_device struct\") decoupled the dma_device\nlifetime from the module reference, so the device can now be released\nwhile a reader is still walking the list.\n\nAdd synchronize_rcu() before the device is freed, so RCU readers are\nguaranteed to have finished. Keep it unconditional: providers that do\nnot implement device_release() free the device themselves once\ndma_async_device_unregister() returns. This call will delay for a grace\nperiod with dma_list_mutex held, which is safe and only teardown path is\ndelayed.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/14578c78405d51fa92e4ada4502a45f537c0fcb8","tags":[]},{"url":"https://git.kernel.org/stable/c/4448a539a0c39141cccc67be6cacde0f35024313","tags":[]},{"url":"https://git.kernel.org/stable/c/4aed7e47a10b94ea3c5171e8d1382081accd2e03","tags":[]},{"url":"https://git.kernel.org/stable/c/8577a5ec4f7e00443015ef99f646def093121a1b","tags":[]},{"url":"https://git.kernel.org/stable/c/ac8ce9f89638d6d79875cca7d8ae42566a9bde15","tags":[]},{"url":"https://git.kernel.org/stable/c/cbb3310a5167e868a5e763e32b9a23b4d50669ee","tags":[]},{"url":"https://git.kernel.org/stable/c/dc750422170a563c7a81f6e49d36bb02c62ae37f","tags":[]},{"url":"https://git.kernel.org/stable/c/fc1f4884f1d46fc7a8cee6e2997ecc9e8d1c7f77","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}