CVE-2023-53586

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

scsi: target: Fix multiple LUN_RESET handling

This fixes a bug where an initiator thinks a LUN_RESET has cleaned up

running commands when it hasn't. The bug was added in commit 51ec502a3266

("target: Delete tmr from list before processing").

The problem occurs when:

1. We have N I/O cmds running in the target layer spread over 2 sessions.

2. The initiator sends a LUN_RESET for each session.

3. session1's LUN_RESET loops over all the running commands from both

sessions and moves them to its local drain_task_list.

4. session2's LUN_RESET does not see the LUN_RESET from session1 because

the commit above has it remove itself. session2 also does not see any

commands since the other reset moved them off the state lists.

5. sessions2's LUN_RESET will then complete with a successful response.

6. sessions2's inititor believes the running commands on its session are

now cleaned up due to the successful response and cleans up the running

commands from its side. It then restarts them.

7. The commands do eventually complete on the backend and the target

starts to return aborted task statuses for them. The initiator will

either throw a invalid ITT error or might accidentally lookup a new

task if the ITT has been reallocated already.

Fix the bug by reverting the patch, and serialize the execution of

LUN_RESETs and Preempt and Aborts.

Also prevent us from waiting on LUN_RESETs in core_tmr_drain_tmr_list,

because it turns out the original patch fixed a bug that was not

mentioned. For LUN_RESET1 core_tmr_drain_tmr_list can see a second

LUN_RESET and wait on it. Then the second reset will run

core_tmr_drain_tmr_list and see the first reset and wait on it resulting in

a deadlock.