Affected: Linux

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

IB/iser: reject a remote invalidation of an unregistered direction

A write command whose data is sent entirely as immediate data is not registered. iser_reg_mem_fastreg() takes the DMA key path and leaves rdma_reg[ISER_DIR_OUT].desc at NULL, while iser_dma_map_task_data() has already set dir[ISER_DIR_OUT].

iser_check_remote_inv() looks at dir[] alone and hands the descriptor to iser_inv_desc(), which reads desc->sig_protected. A target that answers such a command with IB_WR_SEND_WITH_INV faults the initiator. Leaving those commands unregistered is deliberate.

The same function already terminates the connection when a target sends a remote invalidation the initiator did not ask for. A target that invalidates a direction that was never registered is in the same class, so give it the same answer.

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 0 UID: 0 PID: 40 Comm: kworker/u8:2 Not tainted 7.2.0-rc5-ISERHOST-gf5098b6bae76-dirty #3 PREEMPT(lazy) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: rxe_wq do_work RIP: 0010:iser_task_rsp+0x6d6/0xec0 Code: 48 c1 ea 03 80 3c 02 00 0f 85 ba 06 00 00 48 8b 9b 78 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 <…