Bug 2467098 (CVE-2026-43199)

Summary: CVE-2026-43199 kernel: net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's net/mlx5e component. This vulnerability, identified as a "scheduling while atomic" bug, occurs when the mlx5e_ipsec_init_macs() function attempts to query the hardware for a MAC address in an atomic context, which can lead to the system attempting to sleep. A local attacker could potentially trigger this condition, leading to system instability or a kernel panic, resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-05-06 13:04:09 UTC 
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
Comment 1 Keith Grant 2026-05-06 21:05:44 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050645-CVE-2026-43199-6376@gregkh/T