In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: Prevent use after free on completion memory
On driver unload any pending descriptors are flushed at the
time the interrupt is freed:
idxd_dmaengine_drv_remove() ->
drv_disable_wq() ->
idxd_wq_free_irq() ->
idxd_flush_pending_descs().
If there are any descriptors present that need to be flushed this
flow triggers a “not present” page fault as below:
BUG: unable to handle page fault for address: ff391c97c70c9040
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
The address that triggers the fault is the address of the
descriptor that was freed moments earlier via:
drv_disable_wq()->idxd_wq_free_resources()
Fix the use after free by freeing the descriptors after any possible
usage. This is done after idxd_wq_reset() to ensure that the memory
remains accessible during possible completion writes by the device.
git.kernel.org/linus/1beeec45f9ac31eba52478379f70a5fa9c2ad005 (6.2-rc5)
git.kernel.org/stable/c/1beeec45f9ac31eba52478379f70a5fa9c2ad005
git.kernel.org/stable/c/b9e8e3fcfec625fc1c2f68f684448aeeb882625b
launchpad.net/bugs/cve/CVE-2022-48867
nvd.nist.gov/vuln/detail/CVE-2022-48867
security-tracker.debian.org/tracker/CVE-2022-48867
www.cve.org/CVERecord?id=CVE-2022-48867