{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-74584", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-74584" ], "published": "2026-08-22T14:27:04Z", "summary": "RDMA/bnxt_re: zero shared page before exposing to userspace", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/bnxt_re: zero shared page before exposing to userspace\n\nbnxt_re_alloc_ucontext() allocates uctx->shpg via\n__get_free_page(GFP_KERNEL). The buddy allocator does not zero pages\nwithout __GFP_ZERO, so the page contains stale kernel data from\nwhatever object most recently freed it.\n\nThe page is then mapped into userspace via vm_insert_page() under\nBNXT_RE_MMAP_SH_PAGE in bnxt_re_mmap(). The driver only ever writes\n4 bytes (a u32 AVID) at offset BNXT_RE_AVID_OFFT (0x10) inside\nbnxt_re_create_ah(); the remaining 4092 bytes of the page are exposed\nto userspace unsanitised, leaking kernel memory contents.\n\nAny user with access to /dev/infiniband/uverbsX on a host with a\nbnxt_re device (typically rdma group membership) can read this data\nvia a single mmap() at pgoff 0 after IB_USER_VERBS_CMD_GET_CONTEXT.\n\nOther shared pages in the same file already use get_zeroed_page()\ncorrectly:\n\n drivers/infiniband/hw/bnxt_re/ib_verbs.c\n srq->uctx_srq_page = (void *)get_zeroed_page(GFP_KERNEL);\n cq->uctx_cq_page = (void *)get_zeroed_page(GFP_KERNEL);\n\nuctx->shpg is the only outlier. Bring it in line with the existing\nconvention by switching to get_zeroed_page().", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.177", "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-74584" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/53c97e9882f4e747b4ac31b211317c2eba541af9" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/9896bdfd21d918e9f26a52bc6109cc77970ee0b1" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/9128c2411b83a64c0a69d2ff059c741bde25a9cc" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/c19b360fa10c521c0b681875cdaa51545d45a491" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/a3ed2daab02b2a706e882ad31b5c3c4f33cb5bb1" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/e2b143df29003d2704b51f62e9297006953dbacb" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/c75f8ce4baa29ae57fe615c6a2c5101f59b8b89a" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/f6b079629becfa977f9c51fe53ad2e6dcc55ef44" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-25T05:42:41Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.1, "cvss_v3_severity": "High", "scenario": "AV:L - The leak is triggered only through local access to /dev/infiniband/uverbs* via ioctl GET_CONTEXT and mmap(pgoff 0); bnxt_re_mmap maps the shared page with vm_insert_page, and remote RoCE/IB packet handling never reaches this uverbs allocation path.\nAC:L - On a host with bnxt_re loaded, opening uverbs, issuing GET_CONTEXT, and mmap at offset 0 deterministically exposes the unstale page; the attacker controls all syscall parameters and needs no race, special memory layout, or victim-specific state.\nPR:N - Kernel uverbs character devices are created world-accessible (mode 0666) via uverbs_devnode, and ib_uverbs_open performs no capability or root check beyond netns access, so any local process can open the device and allocate a bnxt_re ucontext.\nUI:N - Exploitation requires only attacker-driven open/ioctl/mmap/read syscalls on their own uverbs file descriptor; no cooperative victim action such as mounting filesystems, opening files, or clicking links is needed.\nS:C - On HPC/cloud hosts exposing bnxt_re to tenant containers or shared RDMA workloads, mmap of unstale host-kernel buddy pages leaks host kernel memory across the container/tenant security boundary into an unprivileged workload's address space.\nC:H - __get_free_page without __GFP_ZERO leaves up to 4092 bytes of stale kernel heap/slack data readable per ucontext; repeated opens yield additional pages, disclosing kernel pointers, structures, and other sensitive material beyond a few-byte bounded leak.\nI:N - The flaw only exposes existing kernel memory contents to userspace via mmap; it does not corrupt, overwrite, or modify kernel objects, grant write primitives, or enable code execution through the shared page mapping.\nA:N - Reading the unstale mapped page does not trigger kernel oops, panic, hang, or resource exhaustion; the vulnerable path completes normally and availability is unaffected aside from normal per-context page allocation." } } }