{"id":"CVE-2026-99079","summary":"net/mlx5e: Prevent stale XSK buffer release on refill retry","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Prevent stale XSK buffer release on refill retry\n\nWhen an XDP redirect to an AF_XDP socket fails because its RX ring is\nfull, the XSK core frees the buffer. During the subsequent batched refill\nof a legacy cyclic RQ, mlx5e also releases the WQE's XSK buffer before\nallocating a replacement. If that refill succeeds only partially, a WQE\nleft without a replacement retains its old buffer pointer.\n\nThe buffer can meanwhile be allocated to another WQE. A later refill\nretry can then free the live buffer through the stale pointer and publish\nthe same UMEM frame twice.\n\nMark the WQE as released immediately after the driver-side free. The flag\nis already cleared when a replacement buffer is assigned, so refill\nretries no longer release stale pointers.\n\nThe failure is silent and produces no kernel warning or splat. A\nstandalone legacy cyclic-RQ zero-copy libxsk reproducer, using 64-byte UDP\ntraffic offered at 12 Mpps, detected it: stock stopped after 2,854,914\npackets in 4.094 seconds, with 4,542 xdp_rx_ring_full events and 64\nownership/double-publication errors. With this change it processed\n356,904,225 packets in 30 seconds despite 571,405 xdp_rx_ring_full events,\nwith no ownership or data errors.","modified":"2026-10-28T02:30:48.789787154Z","published":"2026-10-23T12:23:26.458Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99079.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/32bbb870078d467479965c21bbc4960c57eea208"},{"type":"WEB","url":"https://git.kernel.org/stable/c/34d1db2b18e1c1d189e34dd51923e031815f88e3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/639522e5056cade578a324acfa993ec6c9f7f5dc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/655f47477054d19de3b138840be229a1a4490d0c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e01620844c5c88b6fcf819d171df8e3976a0e76f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99079.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99079"},{"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":"3f93f82988bc6b4104314bf9aa485d47fbb7e241"},{"fixed":"32bbb870078d467479965c21bbc4960c57eea208"},{"fixed":"34d1db2b18e1c1d189e34dd51923e031815f88e3"},{"fixed":"639522e5056cade578a324acfa993ec6c9f7f5dc"},{"fixed":"655f47477054d19de3b138840be229a1a4490d0c"},{"fixed":"e01620844c5c88b6fcf819d171df8e3976a0e76f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99079.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.4.0"},{"fixed":"6.6.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.113"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.57"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99079.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:H/I:H/A:H"}]}