From: Leon Romanovsky <leon@kernel.org>
To: security@kernel.org, pomzm67@gmail.com
Cc: selvin.xavier@broadcom.com, kalesh-anakkur.purayil@broadcom.com,
jgg@ziepe.ca, eddie.wai@broadcom.com,
somnath.kotur@broadcom.com, sriharsha.basavapatna@broadcom.com,
devesh.sharma@broadcom.com, dledford@redhat.com,
gregkh@linuxfoundation.org, linux-rdma@vger.kernel.org,
linux-kernel@vger.kernel.org,
Lord Ulf Henrik Holmberg <henrik.holmberg@defensify.se>
Subject: Re: [PATCH] RDMA/bnxt_re: zero shared page before exposing to userspace
Date: Wed, 13 May 2026 14:51:16 -0400 [thread overview]
Message-ID: <177869827695.2371282.12223364694168712496.b4-ty@kernel.org> (raw)
In-Reply-To: <20260509084011.11971-1-pomzm67@gmail.com>
On Sat, 09 May 2026 10:40:11 +0200, pomzm67@gmail.com wrote:
> 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.
>
> [...]
Applied, thanks!
[1/1] RDMA/bnxt_re: zero shared page before exposing to userspace
(no commit info)
Best regards,
--
Leon Romanovsky <leon@kernel.org>
prev parent reply other threads:[~2026-05-13 18:51 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <2026050945-oversight-carefully-93e0@gregkh>
2026-05-09 8:40 ` pomzm67
2026-05-13 18:51 ` Leon Romanovsky [this message]
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