# CVE-2026-98358: IB/iser: reject a remote invalidation of an unregistered direction
> A remote attacker can cause a kernel crash in the Linux IB/iser driver by sending a specific invalidation command for an unregistered direction.
- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-106140, BELL-CVE-2026-98358, DEBIAN-CVE-2026-98358, GHSA-w9qw-7vhq-g4m9, UBUNTU-CVE-2026-98358
## What is CVE-2026-98358?
CVE-2026-98358 is a vulnerability in Linux, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
### Official description
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 <0f> b6 04 02 84 c0 74 06 0f 8e 76 06 00 00 80 7b 20 00 0f 84 3d 04
RSP: 0018:ffff88811b008db8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000001848
RDX: 0000000000000004 RSI: 1ffff11021587b12 RDI: 0000000000000020
RBP: ffff88810adc1ae4 R08: ffff888109b7f860 R09: ffffffff90a922c0
R10: ffff88810adc1a1c R11: 000000000000003c R12: ffff888109b7f800
R13: ffff88810adc1acc R14: ffff888109b7f820 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88818a676000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005afe2b CR3: 000000010af23005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
__ib_process_cq+0xe1/0x390
ib_poll_handler+0x6e/0x200
irq_poll_softirq+0x1df/0x480
? clockevents_program_event+0x2ba/0x860
? __pfx_irq_poll_softirq+0x10/0x10
handle_softirqs+0x18e/0x590
? __pfx_handle_softirqs+0x10/0x10
? __hrtimer_rearm_deferred+0x156/0x450
do_softirq+0x3b/0x60
__local_bh_enable_ip+0x61/0x70
__alloc_skb+0x732/0x890
? _raw_spin_lock_irqsave+0x85/0xe0
? __pfx___alloc_skb+0x10/0x10
? _raw_read_unlock_irqrestore+0x16/0x50
rxe_init_packet+0x16b/0x4f0
prepare_ack_packet+0xb8/0x830
rxe_receiver+0x499/0x9980
? __pfx_rxe_receiver+0x10/0x10
? rxe_completer+0x29e5/0x38c0
? hrtimer_start_range_ns_common+0x75f/0x1730
? hrtimer_start_range_ns+0xa6/0x2c0
? __pfx__raw_spin_lock_irqsave+0x10/0x10
? __pfx_rxe_receiver+0x10/0x10
do_work+0x144/0x470
process_one_work+0x633/0x1030
? assign_work+0x11d/0x370
worker_thread+0x45b/0xd10
? __pfx_worker_thread+0x10/0x10
kthread+0x2c6/0x3b0
? recalc_sigpending+0x15c/0x1e0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x36e/0x5a0
? __pfx_ret_from_fork+0x10/0x10
? __switch_to+0x572/0xdd0
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
Modules linked in:
---[ end trace 0000000000000000 ]---
## Which versions are affected by CVE-2026-98358?
## How do I fix CVE-2026-98358?
Apply the vendor's patch.
## Is CVE-2026-98358 being exploited?
There is no known exploitation of CVE-2026-98358 in the wild and no public exploit code.
## Fix prompt for AI coding agents
```text
Check this codebase for CVE-2026-98358 and fix it if it is affected.
What it is: CVE-2026-98358 is a vulnerability in Linux, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-98358 in the wild and no public exploit code.
Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2026-98358/ (Markdown: https://insights.sbomify.com/CVE-2026-98358/index.md)
```
## Sources
- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98358
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98358
- OSV: https://osv.dev/vulnerability/CVE-2026-98358
---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98358/
Summaries are generated and may contain mistakes; the official description above is the record.