In the Linux kernel, the following vulnerability has been resolved:
nvmet-auth: Synchronize timeout work during SQ teardown
nvmet_auth_sq_free() cancels auth_expired_work with
cancel_delayed_work(). If the work has already started, cancellation does
not wait for the callback. Transport teardown can consequently free or
reuse the queue containing struct nvmet_sq while
nvmet_auth_expired_work() still accesses that SQ.
Add a teardown-specific helper that synchronously drains the delayed work
before freeing authentication state, and use it from nvmet_sq_destroy().
Keep the non-synchronous helper for in-band authentication state cleanup,
where the SQ owner remains alive.
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 9.8
AV:N - The UAF is in nvmet-auth timeout work reached via AUTH_SEND on NVMe-oF targets; nvmet-tcp (and nvmet-rdma) accept remote connections, so a network initiator can arm the timer and tear down the queue over TCP/RDMA.
AC:L - The attacker controls both sides of the race: AUTH_SEND schedules auth_expired_work with an attacker-chosen KATO delay, and closing the connection runs nvmet_sq_destroy(); cancel_delayed_work() does not wait, so the race is repeatable.
PR:N - AUTH_SEND is dispatched as a Fabrics command before nvmet_check_auth_status() and before DH-HMAC-CHAP credentials are verified; discovery accepts any host NQN, so no Linux privileges or verified secrets are required.
UI:N - No victim user action is required; the attacker connects to an already-deployed NVMe-oF target, sends AUTH_SEND to arm the timeout, and disconnects when the work is due.
S:U - The use-after-free corrupts the in-kernel nvmet_sq/queue object on the target host and does not cross a VM, hypervisor, or IOMMU security boundary.
C:H - Transport teardown can free or reuse the queue containing struct nvmet_sq while nvmet_auth_expired_work() still accesses it; that UAF can be leveraged for kernel information disclosure via heap reuse.
I:H - The delayed work writes dhchap_step and dhchap_tid into a potentially freed or reused queue object, giving a kernel UAF write primitive exploitable for memory corruption and control-flow hijacking.
A:H - Racing the timeout callback against SQ teardown is a kernel UAF of the queue and can oops or panic; the work may also dereference sq->ctrl after teardown has already cleared it.
| Attack Vector |
Network |
Scope |
Unchanged |
| Attack Complexity |
Low |
Confidentiality Impact |
High |
| Privileges Required |
None |
Integrity Impact |
High |
| User Interaction |
None |
Availability Impact |
High |
AV:N - The UAF is in nvmet-auth timeout work reached via AUTH_SEND on NVMe-oF targets; nvmet-tcp (and nvmet-rdma) accept remote connections, so a network initiator can arm the timer and tear down the queue over TCP/RDMA.
AC:L - The attacker controls both sides of the race: AUTH_SEND schedules auth_expired_work with an attacker-chosen KATO delay, and closing the connection runs nvmet_sq_destroy(); cancel_delayed_work() does not wait, so the race is repeatable.
PR:N - AUTH_SEND is dispatched as a Fabrics command before nvmet_check_auth_status() and before DH-HMAC-CHAP credentials are verified; discovery accepts any host NQN, so no Linux privileges or verified secrets are required.
UI:N - No victim user action is required; the attacker connects to an already-deployed NVMe-oF target, sends AUTH_SEND to arm the timeout, and disconnects when the work is due.
S:U - The use-after-free corrupts the in-kernel nvmet_sq/queue object on the target host and does not cross a VM, hypervisor, or IOMMU security boundary.
C:H - Transport teardown can free or reuse the queue containing struct nvmet_sq while nvmet_auth_expired_work() still accesses it; that UAF can be leveraged for kernel information disclosure via heap reuse.
I:H - The delayed work writes dhchap_step and dhchap_tid into a potentially freed or reused queue object, giving a kernel UAF write primitive exploitable for memory corruption and control-flow hijacking.
A:H - Racing the timeout callback against SQ teardown is a kernel UAF of the queue and can oops or panic; the work may also dereference sq->ctrl after teardown has already cleared it.
CVSS 3.1