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Findings

CVE-2026-74584

In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: zero shared page before exposing to userspace bnxt_re_alloc_ucontext() allocates uctx…

Published Aug 22, 2026 · updated Oct 14, 2026

In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: zero shared page before exposing to userspace bnxt_re_alloc_ucontext() allocates uctx->shpg via __get_free_page(GFP_KERNEL). The buddy allocator does not zero pages without __GFP_ZERO, so the page contains stale kernel data from whatever object most recently freed it. The page is then mapped into userspace via vm_insert_page() under BNXT_RE_MMAP_SH_PAGE in bnxt_re_mmap(). The driver only ever writes 4 bytes (a u32 AVID) at offset BNXT_RE_AVID_OFFT (0x10) inside bnxt_re_create_ah(); the remaining 4092 bytes of the page are exposed to userspace unsanitised, leaking kernel memory contents. Any user with access to /dev/infiniband/uverbsX on a host with a bnxt_re device (typically rdma group membership) can read this data via a single mmap() at pgoff 0 after IB_USER_VERBS_CMD_GET_CONTEXT. Other shared pages in the same file already use get_zeroed_page() correctly: drivers/infiniband/hw/bnxt_re/ib_verbs.c srq->uctx_srq_page = (void *)get_zeroed_page(GFP_KERNEL); cq->uctx_cq_page = (void *)get_zeroed_page(GFP_KERNEL); uctx->shpg is the only outlier. Bring it in line with the existing convention by switching to get_zeroed_page().

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 22, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: zero shared page before exposing to userspace bnxt_re_alloc_ucontext() allocates uctx->shpg via __get_free_page(GFP_KERNEL). The buddy allocator does not zero pages without __GFP_ZERO, so the page contains stale kernel data from whatever object most recently freed it. The page is then mapped into userspace via vm_ins

  2. Oct 14, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: zero shared page before exposing to userspace bnxt_re_alloc_ucontext() allocates uctx->shpg via __get_free_page(GFP_KERNEL). The buddy allocator does not zero pages without __GFP_ZERO, so the page contains stale kernel data from whatever object most recently freed it. The page is then mapped into userspace via vm_ins

Sources

  • CVE.orgVulnerability recordCVE-2026-74584

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-74584

    30-day exploitation probability 0.2%

    first.org
  • NIST NVDVulnerability recordCVE-2026-74584

    In the Linux kernel, the following vulnerability has been resolved: RDMA/bnxt_re: zero shared page before exposing to userspace bnxt_re_alloc_ucontext() allocates uctx->shpg via __get_free_page(GFP_KERNEL). The buddy allocator does not zero pages without __GFP_ZERO, so the page

    nvd.nist.gov

References