{"id":"CVE-2026-80739","title":"net/mlx5e: TC, Check if flow is PEER before acquiring devcom lock","summary":"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(), an…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < ead5145d290a918b7c3c3141a64b3f827a9e1b6b","Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 607adbda01053abf5f93e322fe39325da8828cb8","Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 585df8643081e6f616579bc52cd49ac823a57c82","Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < ff9e7d5e3500be389ce7a0e46db3a77149830bc9","Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 7165fe321c61ec138850c02f030f274797761f5f","Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 6ddfba2ea98db21b001e0e5c472499156224650c","Linux 5.0"],"published":"2026-09-03","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:31:03.271Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80739","references":[{"url":"https://git.kernel.org/stable/c/ead5145d290a918b7c3c3141a64b3f827a9e1b6b"},{"url":"https://git.kernel.org/stable/c/607adbda01053abf5f93e322fe39325da8828cb8"},{"url":"https://git.kernel.org/stable/c/585df8643081e6f616579bc52cd49ac823a57c82"},{"url":"https://git.kernel.org/stable/c/ff9e7d5e3500be389ce7a0e46db3a77149830bc9"},{"url":"https://git.kernel.org/stable/c/7165fe321c61ec138850c02f030f274797761f5f"},{"url":"https://git.kernel.org/stable/c/6ddfba2ea98db21b001e0e5c472499156224650c"}],"tags":["cve.org"],"epss":0.00173,"epssPercentile":0.06701,"ingestedAt":"2026-11-05T15:02:32.610Z","slug":"CVE-2026-80739","body":"## Overview\n\nIn 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(&comp->lock_key#2);\n  lock(&comp->lock_key#2);\n *** DEADLOCK ***\nCall Trace:\n <TASK>\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 </TASK>\n\n## Affected\n\n- `Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < ead5145d290a918b7c3c3141a64b3f827a9e1b6b`\n- `Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 607adbda01053abf5f93e322fe39325da8828cb8`\n- `Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 585df8643081e6f616579bc52cd49ac823a57c82`\n- `Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < ff9e7d5e3500be389ce7a0e46db3a77149830bc9`\n- `Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 7165fe321c61ec138850c02f030f274797761f5f`\n- `Linux >= 04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d < 6ddfba2ea98db21b001e0e5c472499156224650c`\n- `Linux 5.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}