{"id":"CVE-2026-89856","summary":"scsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation\n\nha-\u003emsix_count is u16, but ha-\u003emax_req_queues, ha-\u003emax_rsp_queues and\nha-\u003emax_qpairs are u8. Deriving the queue count as\n\"ha-\u003emax_req_queues = ha-\u003emsix_count - 1\" therefore truncates: a board\n(or a misconfigured/malicious hot-plugged device) advertising 257 MSI-X\nvectors yields msix_count - 1 == 256, which truncates to 0. An MSI-X\ncount of 1 zeroes it as well, and in target mode the subsequent\n\"ha-\u003emax_req_queues--\" then underflows 0 to 255.\n\nWhen the count is 0, qla2x00_alloc_queues() calls\nkzalloc_objs(struct req_que *, 0), which returns ZERO_SIZE_PTR. That is\nnot NULL, so the allocation check passes and the following\n\"ha-\u003ereq_q_map[0] = req\" dereferences ZERO_SIZE_PTR, corrupting memory\nor crashing the kernel.\n\nAdd qla_calc_queue_count() to clamp the derived value into\n[1, QLA_MAX_QUEUES - 1] so it always fits in u8 and is never zero, and\nuse it at all three derivation sites (qla25xx_iospace_config(),\nqla83xx_iospace_config() and qla24xx_enable_msix()). Also guard the\ntarget-mode decrement so it cannot reintroduce a zero (which would in\nturn underflow max_qpairs).","modified":"2026-09-18T03:48:33.606294397Z","published":"2026-09-16T10:31:29.517Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89856.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2efe50b2da829909023de4a2eb87badb7cfa53cc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/33c77254e6e91f37c72c7fad4051777452b10de8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7a448f5ed0b283dbde4e9183dd1e98c221432dab"},{"type":"WEB","url":"https://git.kernel.org/stable/c/802068b9b683b8008fcccbf6e9ad133e597ec87c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9eeddbeaa896f39d943644b16d83a6ad0ceab255"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cf623d32761b00f221a9cfded3303d56e84b429d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e80adfeac61b4d5db7ffe0f5af43999c33a4145e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ebfd35c64433821bd5619a6d07ccc2df8b5b1de3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89856.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89856"},{"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":"d74595278f4ab192af66d9e60a9087464638beee"},{"fixed":"cf623d32761b00f221a9cfded3303d56e84b429d"},{"fixed":"9eeddbeaa896f39d943644b16d83a6ad0ceab255"},{"fixed":"802068b9b683b8008fcccbf6e9ad133e597ec87c"},{"fixed":"e80adfeac61b4d5db7ffe0f5af43999c33a4145e"},{"fixed":"2efe50b2da829909023de4a2eb87badb7cfa53cc"},{"fixed":"7a448f5ed0b283dbde4e9183dd1e98c221432dab"},{"fixed":"33c77254e6e91f37c72c7fad4051777452b10de8"},{"fixed":"ebfd35c64433821bd5619a6d07ccc2df8b5b1de3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89856.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.10.0"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.51"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89856.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}