{"id":"CVE-2026-43464","title":"net/mlx5e: RX, Fix XDP multi-buf frag counting for legacy RQ","summary":"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() …","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 72328f25755ee966724f46e3a0e8e59bef2091ba < 1106412414dc3ee62999115be10ca83199b02108","Linux >= 0049fd63881505566824e88cfa624638f921c808 < 9488ee96b4f53d2aed474c744f0ed64f61d1dcc9","Linux >= afd5ba577c10639f62e8120df67dc70ea4b61176 < c74557495efb4bd0adefdfc8678ecdbc82a06da3","Linux >= afd5ba577c10639f62e8120df67dc70ea4b61176 < 03cb50e5b74fce8bf6d92b860371b66253cf0f8d","Linux >= afd5ba577c10639f62e8120df67dc70ea4b61176 < a6413e6f6c9d9bb9833324cb3753582f7bc0f2fa","Linux d969645b9b7810289bf3c353ea06957373756b8e","Linux >= 6.6.115 < 6.6.160","Linux >= 6.12.56 < 6.12.114","Linux >= 6.17.6 < 6.18","Linux 6.18"],"published":"2026-05-08","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:40:49.291Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43464","references":[{"url":"https://git.kernel.org/stable/c/1106412414dc3ee62999115be10ca83199b02108"},{"url":"https://git.kernel.org/stable/c/9488ee96b4f53d2aed474c744f0ed64f61d1dcc9"},{"url":"https://git.kernel.org/stable/c/c74557495efb4bd0adefdfc8678ecdbc82a06da3"},{"url":"https://git.kernel.org/stable/c/03cb50e5b74fce8bf6d92b860371b66253cf0f8d"},{"url":"https://git.kernel.org/stable/c/a6413e6f6c9d9bb9833324cb3753582f7bc0f2fa"}],"tags":["cve.org"],"epss":0.00732,"epssPercentile":0.53564,"ingestedAt":"2026-10-21T12:48:53.637Z","slug":"CVE-2026-43464","body":"## Overview\n\nIn 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   <TASK>\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.\n\n## Affected\n\n- `Linux >= 72328f25755ee966724f46e3a0e8e59bef2091ba < 1106412414dc3ee62999115be10ca83199b02108`\n- `Linux >= 0049fd63881505566824e88cfa624638f921c808 < 9488ee96b4f53d2aed474c744f0ed64f61d1dcc9`\n- `Linux >= afd5ba577c10639f62e8120df67dc70ea4b61176 < c74557495efb4bd0adefdfc8678ecdbc82a06da3`\n- `Linux >= afd5ba577c10639f62e8120df67dc70ea4b61176 < 03cb50e5b74fce8bf6d92b860371b66253cf0f8d`\n- `Linux >= afd5ba577c10639f62e8120df67dc70ea4b61176 < a6413e6f6c9d9bb9833324cb3753582f7bc0f2fa`\n- `Linux d969645b9b7810289bf3c353ea06957373756b8e`\n- `Linux >= 6.6.115 < 6.6.160`\n- `Linux >= 6.12.56 < 6.12.114`\n- `Linux >= 6.17.6 < 6.18`\n- `Linux 6.18`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}