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GHSA-MQQ3-JV52-Q32J

Vulnerability from github – Published: 2026-09-03 15:32 – Updated: 2026-09-03 15:32
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: TC, Check if flow is PEER before acquiring devcom lock

In case __mlx5e_add_fdb_flow() fails in lower levels, the flow is deleted via mlx5e_tc_del_flow(), and mlx5e_tc_del_flow() is acquiring ESW devcom lock without condition. In addition, in case of peer_flow, __mlx5e_add_fdb_flow() is called while holding ESW devcom comp lock. This results in an AA deadlock.

To fix this, introduce a new PEER flag that is set on flows created as peer flows (the duplicate flows on peer devices), and check it in mlx5e_tc_del_flow() before acquiring ESW devcom lock.

Lockdep splat:

WARNING: possible recursive locking detected

Possible unsafe locking scenario: CPU0 ---- lock(&comp->lock_key#2); lock(&comp->lock_key#2); *** DEADLOCK *** Call Trace: dump_stack_lvl+0x69/0xa0 print_deadlock_bug.cold+0xbd/0xca __lock_acquire+0x1671/0x2ec0 lock_acquire+0x10e/0x2e0 down_read+0x95/0x430 mlx5_devcom_for_each_peer_begin+0x4e/0xe0 [mlx5_core] mlx5e_tc_del_flow+0x11d/0xa70 [mlx5_core] mlx5e_flow_put+0x99/0x100 [mlx5_core] __mlx5e_add_fdb_flow+0x409/0xf00 [mlx5_core] mlx5e_configure_flower+0x2a86/0x4100 [mlx5_core] mlx5e_rep_setup_tc_cls_flower+0x12f/0x1b0 [mlx5_core] mlx5e_rep_setup_tc_cb+0x153/0x750 [mlx5_core] tc_setup_cb_add+0x1dc/0x470 fl_change+0x2f4d/0x626d [cls_flower] tc_new_tfilter+0x79b/0x2310 rtnetlink_rcv_msg+0x778/0xad0 do_syscall_64+0x70/0x960 entry_SYSCALL_64_after_hwframe+0x4b/0x53

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{
  "affected": [],
  "aliases": [
    "CVE-2026-80739"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-03T13:06:13Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: TC, Check if flow is PEER before acquiring devcom lock\n\nIn case __mlx5e_add_fdb_flow() fails in lower levels, the flow is\ndeleted via mlx5e_tc_del_flow(), and mlx5e_tc_del_flow() is acquiring\nESW devcom lock without condition. In addition, in case of peer_flow,\n__mlx5e_add_fdb_flow() is called while holding ESW devcom comp lock.\nThis results in an AA deadlock.\n\nTo fix this, introduce a new PEER flag that is set on flows created as\npeer flows (the duplicate flows on peer devices), and check it in\nmlx5e_tc_del_flow() before acquiring ESW devcom lock.\n\nLockdep splat:\n============================================\nWARNING: possible recursive locking detected\n============================================\n Possible unsafe locking scenario:\n       CPU0\n       ----\n  lock(\u0026comp-\u003elock_key#2);\n  lock(\u0026comp-\u003elock_key#2);\n *** DEADLOCK ***\nCall Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0x69/0xa0\n print_deadlock_bug.cold+0xbd/0xca\n __lock_acquire+0x1671/0x2ec0\n lock_acquire+0x10e/0x2e0\n down_read+0x95/0x430\n mlx5_devcom_for_each_peer_begin+0x4e/0xe0 [mlx5_core]\n mlx5e_tc_del_flow+0x11d/0xa70 [mlx5_core]\n mlx5e_flow_put+0x99/0x100 [mlx5_core]\n __mlx5e_add_fdb_flow+0x409/0xf00 [mlx5_core]\n mlx5e_configure_flower+0x2a86/0x4100 [mlx5_core]\n mlx5e_rep_setup_tc_cls_flower+0x12f/0x1b0 [mlx5_core]\n mlx5e_rep_setup_tc_cb+0x153/0x750 [mlx5_core]\n tc_setup_cb_add+0x1dc/0x470\n fl_change+0x2f4d/0x626d [cls_flower]\n tc_new_tfilter+0x79b/0x2310\n rtnetlink_rcv_msg+0x778/0xad0\n do_syscall_64+0x70/0x960\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n \u003c/TASK\u003e",
  "id": "GHSA-mqq3-jv52-q32j",
  "modified": "2026-09-03T15:32:15Z",
  "published": "2026-09-03T15:32:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80739"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/585df8643081e6f616579bc52cd49ac823a57c82"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/607adbda01053abf5f93e322fe39325da8828cb8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6ddfba2ea98db21b001e0e5c472499156224650c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7165fe321c61ec138850c02f030f274797761f5f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ff9e7d5e3500be389ce7a0e46db3a77149830bc9"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}



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