{"id":"CVE-2026-80739","summary":"net/mlx5e: TC, Check if flow is PEER before acquiring devcom lock","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(&comp-\u003elock_key#2);\n  lock(&comp-\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","modified":"2026-09-05T03:48:34.751928943Z","published":"2026-09-03T08:21:53.739Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80739.json","cna_assigner":"Linux"},"references":[{"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"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80739.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80739"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"04de7dda7394fa9c2b0fc9cec65661d9b4f0d04d"},{"fixed":"607adbda01053abf5f93e322fe39325da8828cb8"},{"fixed":"585df8643081e6f616579bc52cd49ac823a57c82"},{"fixed":"ff9e7d5e3500be389ce7a0e46db3a77149830bc9"},{"fixed":"7165fe321c61ec138850c02f030f274797761f5f"},{"fixed":"6ddfba2ea98db21b001e0e5c472499156224650c"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80739.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0.0"},{"fixed":"6.6.152"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.104"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.45"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80739.json"}}],"schema_version":"1.9.0"}