{"id":"CVE-2026-43464","summary":"net/mlx5e: RX, Fix XDP multi-buf frag counting for legacy RQ","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: RX, Fix XDP multi-buf frag counting for legacy RQ\n\nXDP multi-buf programs can modify the layout of the XDP buffer when the\nprogram calls bpf_xdp_pull_data() or bpf_xdp_adjust_tail(). The\nreferenced commit in the fixes tag corrected the assumption in the mlx5\ndriver that the XDP buffer layout doesn't change during a program\nexecution. However, this fix introduced another issue: the dropped\nfragments still need to be counted on the driver side to avoid page\nfragment reference counting issues.\n\nSuch issue can be observed with the\ntest_xdp_native_adjst_tail_shrnk_data selftest when using a payload of\n3600 and shrinking by 256 bytes (an upcoming selftest patch): the last\nfragment gets released by the XDP code but doesn't get tracked by the\ndriver. This results in a negative pp_ref_count during page release and\nthe following splat:\n\n  WARNING: include/net/page_pool/helpers.h:297 at mlx5e_page_release_fragmented.isra.0+0x4a/0x50 [mlx5_core], CPU#12: ip/3137\n  Modules linked in: [...]\n  CPU: 12 UID: 0 PID: 3137 Comm: ip Not tainted 6.19.0-rc3+ #12 NONE\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\n  RIP: 0010:mlx5e_page_release_fragmented.isra.0+0x4a/0x50 [mlx5_core]\n  [...]\n  Call Trace:\n   \u003cTASK\u003e\n   mlx5e_dealloc_rx_wqe+0xcb/0x1a0 [mlx5_core]\n   mlx5e_free_rx_descs+0x7f/0x110 [mlx5_core]\n   mlx5e_close_rq+0x50/0x60 [mlx5_core]\n   mlx5e_close_queues+0x36/0x2c0 [mlx5_core]\n   mlx5e_close_channel+0x1c/0x50 [mlx5_core]\n   mlx5e_close_channels+0x45/0x80 [mlx5_core]\n   mlx5e_safe_switch_params+0x1a5/0x230 [mlx5_core]\n   mlx5e_change_mtu+0xf3/0x2f0 [mlx5_core]\n   netif_set_mtu_ext+0xf1/0x230\n   do_setlink.isra.0+0x219/0x1180\n   rtnl_newlink+0x79f/0xb60\n   rtnetlink_rcv_msg+0x213/0x3a0\n   netlink_rcv_skb+0x48/0xf0\n   netlink_unicast+0x24a/0x350\n   netlink_sendmsg+0x1ee/0x410\n   __sock_sendmsg+0x38/0x60\n   ____sys_sendmsg+0x232/0x280\n   ___sys_sendmsg+0x78/0xb0\n   __sys_sendmsg+0x5f/0xb0\n   [...]\n   do_syscall_64+0x57/0xc50\n\nThis patch fixes the issue by doing page frag counting on all the\noriginal XDP buffer fragments for all relevant XDP actions (XDP_TX ,\nXDP_REDIRECT and XDP_PASS). This is basically reverting to the original\ncounting before the commit in the fixes tag.\n\nAs frag_page is still pointing to the original tail, the nr_frags\nparameter to xdp_update_skb_frags_info() needs to be calculated\nin a different way to reflect the new nr_frags.","modified":"2026-10-28T02:30:58.818513398Z","published":"2026-05-08T14:22:26.039Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43464.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/03cb50e5b74fce8bf6d92b860371b66253cf0f8d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1106412414dc3ee62999115be10ca83199b02108"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9488ee96b4f53d2aed474c744f0ed64f61d1dcc9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a6413e6f6c9d9bb9833324cb3753582f7bc0f2fa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c74557495efb4bd0adefdfc8678ecdbc82a06da3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43464.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43464"},{"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":"72328f25755ee966724f46e3a0e8e59bef2091ba"},{"fixed":"1106412414dc3ee62999115be10ca83199b02108"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0049fd63881505566824e88cfa624638f921c808"},{"fixed":"9488ee96b4f53d2aed474c744f0ed64f61d1dcc9"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"afd5ba577c10639f62e8120df67dc70ea4b61176"},{"fixed":"c74557495efb4bd0adefdfc8678ecdbc82a06da3"},{"fixed":"03cb50e5b74fce8bf6d92b860371b66253cf0f8d"},{"fixed":"a6413e6f6c9d9bb9833324cb3753582f7bc0f2fa"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.6.115"},{"fixed":"6.6.160"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.12.56"},{"fixed":"6.12.114"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.17.6"},{"fixed":"6.18"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d969645b9b7810289bf3c353ea06957373756b8e"}]}],"versions":["v6.6.159","v6.6.158","v6.6.157","v6.6.156","v6.6.155","v6.6.154","v6.6.153","v6.6.152","v6.6.151","v6.6.150","v6.6.149","v6.6.148","v6.6.147","v6.6.146","v6.6.145","v6.6.144","v6.6.143","v6.6.142","v6.6.141","v6.6.140","v6.6.139","v6.6.138","v6.6.137","v6.6.136","v6.6.135","v6.6.134","v6.6.133","v6.6.132","v6.6.131","v6.6.130","v6.6.129","v6.6.128","v6.6.127","v6.6.126","v6.6.125","v6.6.124","v6.6.123","v6.6.122","v6.6.121","v6.6.120","v6.6.119","v6.6.118","v6.6.117","v6.6.116","v6.6.115","v6.12.113","v6.12.112","v6.12.111","v6.12.110","v6.12.109","v6.12.108","v6.12.107","v6.12.106","v6.12.105","v6.12.104","v6.12.103","v6.12.102","v6.12.101","v6.12.100","v6.12.99","v6.12.98","v6.12.97","v6.12.96","v6.12.95","v6.12.94","v6.12.93","v6.12.92","v6.12.91","v6.12.90","v6.12.89","v6.12.88","v6.12.87","v6.12.86","v6.12.85","v6.12.84","v6.12.83","v6.12.82","v6.12.81","v6.12.80","v6.12.79","v6.12.78","v6.12.77","v6.12.76","v6.12.75","v6.12.74","v6.12.73","v6.12.72","v6.12.71","v6.12.70","v6.12.69","v6.12.68","v6.12.67","v6.12.66","v6.12.65","v6.12.64","v6.12.63","v6.12.62","v6.12.61","v6.12.60","v6.12.59","v6.12.58","v6.12.57","v6.12.56","v6.17.13","v6.17.12","v6.17.11","v6.17.10","v6.17.9","v6.17.8","v6.17.7","v6.17.6"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43464.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.114"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.19"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.18.0"},{"fixed":"6.19.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43464.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}