{"cve":"CVE-2021-47199","nvd":{"published":"2024-04-10T19:15:48.037","modified":"2026-06-17T04:16:53.560","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: CT, Fix multiple allocations and memleak of mod acts\n\nCT clear action offload adds additional mod hdr actions to the\nflow's original mod actions in order to clear the registers which\nhold ct_state.\nWhen such flow also includes encap action, a neigh update event\ncan cause the driver to unoffload the flow and then reoffload it.\n\nEach time this happens, the ct clear handling adds that same set\nof mod hdr actions to reset ct_state until the max of mod hdr\nactions is reached.\n\nAlso the driver never releases the allocated mod hdr actions and\ncausing a memleak.\n\nFix above two issues by moving CT clear mod acts allocation\ninto the parsing actions phase and only use it when offloading the rule.\nThe release of mod acts will be done in the normal flow_put().\n\n backtrace:\n    [<000000007316e2f3>] krealloc+0x83/0xd0\n    [<00000000ef157de1>] mlx5e_mod_hdr_alloc+0x147/0x300 [mlx5_core]\n    [<00000000970ce4ae>] mlx5e_tc_match_to_reg_set_and_get_id+0xd7/0x240 [mlx5_core]\n    [<0000000067c5fa17>] mlx5e_tc_match_to_reg_set+0xa/0x20 [mlx5_core]\n    [<00000000d032eb98>] mlx5_tc_ct_entry_set_registers.isra.0+0x36/0xc0 [mlx5_core]\n    [<00000000fd23b869>] mlx5_tc_ct_flow_offload+0x272/0x1f10 [mlx5_core]\n    [<000000004fc24acc>] mlx5e_tc_offload_fdb_rules.part.0+0x150/0x620 [mlx5_core]\n    [<00000000dc741c17>] mlx5e_tc_encap_flows_add+0x489/0x690 [mlx5_core]\n    [<00000000e92e49d7>] mlx5e_rep_update_flows+0x6e4/0x9b0 [mlx5_core]\n    [<00000000f60f5602>] mlx5e_rep_neigh_update+0x39a/0x5d0 [mlx5_core]","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401"],"references":["https://git.kernel.org/stable/c/486e8de6e233ff2999493533c6259d1cb538653b","https://git.kernel.org/stable/c/806401c20a0f9c51b6c8fd7035671e6ca841f6c2","https://git.kernel.org/stable/c/486e8de6e233ff2999493533c6259d1cb538653b","https://git.kernel.org/stable/c/806401c20a0f9c51b6c8fd7035671e6ca841f6c2"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:48:32.179249784+00:00"},"epss":{"cve":"CVE-2021-47199","score":0.00196,"percentile":0.09369,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}