CVE-2022-49625: sfc: fix kernel panic when creating VF

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: sfc: fix kernel panic when creating VF When creating VFs a kernel panic can happen when calling to efx_ef10_try_update_nic_stats_vf. When releasing a DMA coherent buffer, sometimes, I don't know in what specific circumstances, it has to unmap memory with vunmap. It is disallowed to do that in IRQ context or with BH disabled. Otherwise, we hit this line in vunmap, causing the crash: BUG_ON(in_interrupt()); This patch reenables BH to release the buffer. Log messages when the bug is hit: kernel BUG at mm/vmalloc.c:2727! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 6 PID: 1462 Comm: NetworkManager Kdump: loaded Tainted: G I --------- --- 5.14.0-119.el9.x86_64 #1 Hardware name: Dell Inc. PowerEdge R740/06WXJT, BIOS 2.8.2 08/27/2020 RIP: 0010:vunmap+0x2e/0x30 ...skip... Call Trace: __iommu_dma_free+0x96/0x100 efx_nic_free_buffer+0x2b/0x40 [sfc] efx_ef10_try_update_nic_stats_vf+0x14a/0x1c0 [sfc] efx_ef10_update_stats_vf+0x18/0x40 [sfc] efx_start_all+0x15e/0x1d0 [sfc] efx_net_open+0x5a/0xe0 [sfc] __dev_open+0xe7/0x1a0 __dev_change_flags+0x1d7/0x240 dev_change_flags+0x21/0x60 ...skip...

Affected products

Linux kernel: from 4.2 before 4.9.324; from 4.10 before 4.14.289; from 4.15 before 4.19.253; from 4.20 before 5.4.207; from 5.5 before 5.10.132; from 5.11 before 5.15.56 — fixed in 4.14.289, 4.19.253, 4.9.324, 5.10.132, 5.15.56, 5.18.13

How to fix

Upgrade to a fixed version: Linux kernel 4.14.289, 4.19.253, 4.9.324, 5.10.132. Check the vendor advisory for mitigations.

References

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