CVE-2022-49703 scsi: ibmvfc: Store vhost pointer during subcrq allocation
A null pointer dereference in the ibmvfc driver causes a kernel crash during kexec/kdump on Power 9 systems with legacy XICS interrupts.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49703?
CVE-2022-49703 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 2025. 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:
scsi: ibmvfc: Store vhost pointer during subcrq allocation
Currently the back pointer from a queue to the vhost adapter isn't set until after subcrq interrupt registration. The value is available when a queue is first allocated and can/should be also set for primary and async queues as well as subcrqs.
This fixes a crash observed during kexec/kdump on Power 9 with legacy XICS interrupt controller where a pending subcrq interrupt from the previous kernel can be replayed immediately upon IRQ registration resulting in dereference of a garbage backpointer in ibmvfc_interrupt_scsi().
Kernel attempted to read user page (58) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on read at 0x00000058 Faulting instruction address: 0xc008000003216a08 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [c008000003216a08] ibmvfc_interrupt_scsi+0x40/0xb0 [ibmvfc] LR [c0000000082079e8] __handle_irq_event_percpu+0x98/0x270 Call Trace: [c000000047fa3d80] [c0000000123e6180] 0xc0000000123e6180 (unreliable) [c000000047fa3df0] [c0000000082079e8] __handle_irq_event_percpu+0x98/0x270 [c000000047fa3ea0] [c000000008207d18] handle_irq_event+0x98/0x188 [c000000047fa3ef0] [c00000000820f564] handle_fasteoi_irq+0xc4/0x310 [c000000047fa3f40] [c000000008205c60] generic_handle_irq+0x50/0x80 [c000000047fa3f60] [c000000008015c40] __do_irq+0x70/0x1a0 [c000000047fa3f90] [c000000008016d7c] __do_IRQ+0x9c/0x130 [c000000014622f60] [0000000020000000] 0x20000000 [c000000014622ff0] [c000000008016e50] do_IRQ+0x40/0xa0 [c000000014623020] [c000000008017044] replay_soft_interrupts+0x194/0x2f0 [c000000014623210] [c0000000080172a8] arch_local_irq_restore+0x108/0x170 [c000000014623240] [c000000008eb1008] _raw_spin_unlock_irqrestore+0x58/0xb0 [c000000014623270] [c00000000820b12c] __setup_irq+0x49c/0x9f0 [c000000014623310] [c00000000820b7c0] request_threaded_irq+0x140/0x230 [c000000014623380] [c008000003212a50] ibmvfc_register_scsi_channel+0x1e8/0x2f0 [ibmvfc] [c000000014623450] [c008000003213d1c] ibmvfc_init_sub_crqs+0xc4/0x1f0 [ibmvfc] [c0000000146234d0] [c0080000032145a8] ibmvfc_reset_crq+0x150/0x210 [ibmvfc] [c000000014623550] [c0080000032147c8] ibmvfc_init_crq+0x160/0x280 [ibmvfc] [c0000000146235f0] [c00800000321a9cc] ibmvfc_probe+0x2a4/0x530 [ibmvfc]
Weakness: CWE-476
Which versions are affected by CVE-2022-49703?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49703?
Apply the vendor's patch.
Is CVE-2022-49703 being exploited?
There is no known exploitation of CVE-2022-49703 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49703, GHSA-fx3x-j43m-j597, UBUNTU-CVE-2022-49703.