Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected daa6eda65a53e5addf86c6bc829129ff51b08bda before ec6ecab1b7577ae555ee6b81480814d123dd9ec0; affected daa6eda65a53e5addf86c6bc829129ff51b08bda before cef2cedb6f7a394b278775b3d6ffb9b20ecd61db; affected daa6eda65a53e5addf86c6bc829129ff51b08bda before a34a230ccea1b8b667ae59dca11295a2c8f81738; affected daa6eda65a53e5addf86c6bc829129ff51b08bda before 1d35a17f1c2ed4154731895694a1a3557f0da766; affected daa6eda65a53e5addf86c6bc829129ff51b08bda before 27c0f718d3b3c99e6d315308e95d987d0382a8a8 |
| Linux / Linux | affected 2.6.13; unaffected 0 before 2.6.13; unaffected 6.6.160 through 6.6.*; unaffected 6.12.114 through 6.12.*; unaffected 6.18.58 through 6.18.*; unaffected 7.2.11 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/ec6ecab1b7577ae555ee6b81480814d123dd9ec0
- https://git.kernel.org/stable/c/cef2cedb6f7a394b278775b3d6ffb9b20ecd61db
- https://git.kernel.org/stable/c/a34a230ccea1b8b667ae59dca11295a2c8f81738
- https://git.kernel.org/stable/c/1d35a17f1c2ed4154731895694a1a3557f0da766
- https://git.kernel.org/stable/c/27c0f718d3b3c99e6d315308e95d987d0382a8a8