{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-99079", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.389Z", "datePublished": "2026-10-23T12:23:26.458Z", "dateUpdated": "2026-10-24T14:10:21.247Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-24T14:10:21.247Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - UDP datagrams reaching mlx5 drive mlx5e_completion_event() -> mlx5e_napi_poll() -> mlx5e_poll_rx_cq()/XDP redirect, then mlx5e_napi_xsk_post() -> mlx5e_post_rx_wqes() -> patched mlx5e_xsk_free_rx_wqe(); sustained routable traffic fills the XSK RX ring and triggers stale release.\nAC:L - A sender can sustain small-packet traffic until __xsk_rcv_zc() reports RX-ring-full and mlx5e_xsk_alloc_rx_wqes_batched() refills only part of the missing WQEs; retries are deterministic and require no uncontrolled race or memory layout.\nPR:N - The NIC-CQE/NAPI receive path contains no capability or authentication check; xsk_create()'s CAP_NET_RAW check applies to victim-side AF_XDP provisioning, while the remote UDP sender needs no privileges.\nUI:N - Once the zero-copy XSK pool and XDP redirect are active, xsk_rcv_zc() failure, mlx5e_napi_xsk_post(), and refill retries occur automatically as packets arrive, without further victim action.\nS:U - mlx5e_xsk_free_rx_wqe() corrupts the host kernel's xsk_buff_pool and mlx5 receive state without crossing a VM, IOMMU, or other security-authority boundary.\nC:H - Duplicate xdp_buff_xsk ownership lets repeated successful __xsk_rcv_zc() calls invoke unbounded xp_release(); in unaligned-UMEM mode, free_heads_cnt can write kernel pointers past the flexible free_heads[] array, yielding heap corruption exploitable for arbitrary disclosure.\nI:H - The duplicate WQEs can make xp_release() write beyond free_heads[], while xp_get_xskb() later trusts pointers popped through the corrupted count; this supplies out-of-bounds and corrupted-pointer write primitives capable of control-flow hijacking.\nA:H - The free_heads[] overflow or a bogus xskb consumed by xp_get_xskb() can oops or panic; additionally, the dma_dev_need_sync refill path can store NULL on allocation failure and have the stale retry pass it to xsk_buff_free()." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/mellanox/mlx5/core/en_rx.c" ], "versions": [ { "version": "3f93f82988bc6b4104314bf9aa485d47fbb7e241", "lessThan": "32bbb870078d467479965c21bbc4960c57eea208", "status": "affected", "versionType": "git" }, { "version": "3f93f82988bc6b4104314bf9aa485d47fbb7e241", "lessThan": "34d1db2b18e1c1d189e34dd51923e031815f88e3", "status": "affected", "versionType": "git" }, { "version": "3f93f82988bc6b4104314bf9aa485d47fbb7e241", "lessThan": "639522e5056cade578a324acfa993ec6c9f7f5dc", "status": "affected", "versionType": "git" }, { "version": "3f93f82988bc6b4104314bf9aa485d47fbb7e241", "lessThan": "655f47477054d19de3b138840be229a1a4490d0c", "status": "affected", "versionType": "git" }, { "version": "3f93f82988bc6b4104314bf9aa485d47fbb7e241", "lessThan": "e01620844c5c88b6fcf819d171df8e3976a0e76f", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/mellanox/mlx5/core/en_rx.c" ], "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.2.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/32bbb870078d467479965c21bbc4960c57eea208" }, { "url": "https://git.kernel.org/stable/c/34d1db2b18e1c1d189e34dd51923e031815f88e3" }, { "url": "https://git.kernel.org/stable/c/639522e5056cade578a324acfa993ec6c9f7f5dc" }, { "url": "https://git.kernel.org/stable/c/655f47477054d19de3b138840be229a1a4490d0c" }, { "url": "https://git.kernel.org/stable/c/e01620844c5c88b6fcf819d171df8e3976a0e76f" } ], "title": "net/mlx5e: Prevent stale XSK buffer release on refill retry", "x_generator": { "engine": "bippy-1.2.0" } } } }