CVE-2026-99019

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

scsi: ch: Do not keep references to data transfer element devices

ch readconfig() looks up the scsi device of every data transfer element whose SCSI id the changer reports in READ ELEMENT STATUS, and stores it in ch->dt[]. scsi device lookup() takes a reference, and nothing ever drops it: ch destroy() frees the array with kfree(). ch->dt[] is read nowhere else - it only supplies the vendor, model and revision printed in the same loop.

Once such a drive is removed, its scsi device can never be released. It stays on the host's device list at its address, so a new device there is refused by anything that walks the list - target core pscsi reports "scsi device get() failed for H:C:T:L" - and the low-level driver's module can no longer be unloaded. Only a reboot recovers.

It shows with any changer that reports its drives' ids; with the mhvtl virtual library (IBM 3573-TL personality), each create and remove of a library with four drives leaves four references behind, counted by the module's use count in lsmod. With ch not bound the count is unchanged, and with this patch applied it is unchanged too.

Drop the reference as soon as the name has been printed, and remove the now unused dt[] array. That also removes the array leaked when ch probe() fails after ch readconfig().

The same leak was reported with an RFC patch in 2022, which was not merged.