CVE-2023-54184 scsi: target: iscsit: Free cmds before session free
A use-after-free vulnerability in the Linux kernel iSCSI target allows attackers to cause a denial of service via a NULL pointer dereference.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54184?
CVE-2023-54184 is a critical use after free vulnerability in Linux, published on 30 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsit: Free cmds before session free
Commands from recovery entries are freed after session has been closed. That leads to use-after-free at command free or NPE with such call trace:
Time2Retain timer expired for SID: 1, cleaning up iSCSI session. BUG: kernel NULL pointer dereference, address: 0000000000000140 RIP: 0010:sbitmap_queue_clear+0x3a/0xa0 Call Trace: target_release_cmd_kref+0xd1/0x1f0 [target_core_mod] transport_generic_free_cmd+0xd1/0x180 [target_core_mod] iscsit_free_cmd+0x53/0xd0 [iscsi_target_mod] iscsit_free_connection_recovery_entries+0x29d/0x320 [iscsi_target_mod] iscsit_close_session+0x13a/0x140 [iscsi_target_mod] iscsit_check_post_dataout+0x440/0x440 [iscsi_target_mod] call_timer_fn+0x24/0x140
Move cleanup of recovery enrties to before session freeing.
Which versions are affected by CVE-2023-54184?
How do I fix CVE-2023-54184?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2023-54184 being exploited?
There is no known exploitation of CVE-2023-54184 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54184, DEBIAN-CVE-2023-54184, GHSA-mhc4-7fcr-wrj3, UBUNTU-CVE-2023-54184.