From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EAAD1357D0F; Thu, 2 Jul 2026 16:36:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010221; cv=none; b=MS2wZSW73L+1uHqonSvUQ4j5Pvx+zUY7cCgN1ENatSnt8eTBODWaIrO7letFfeVQf8zZ1cDbpiCLr0IEk4hcd3vh8Yh+//hLL88kICrmVhTmXFvvY2FZ/s6Y2LlYzpvsTH3QBNKrBAtuANXdzfDB1uogoWCGOUD/LLBR2LP70Lg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010221; c=relaxed/simple; bh=DkGMyF8KTnbL2FBn50ywfsLkbe1W+5rVneZVozdUrPw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rnjg82jxwnfv5kEznsIZbRMsYt+xH3oJ9HdraihlMBAKF7SPXNKQzqFI2Q1ztOVmA+g9kQWSu12fG3F3QyHAhk9J42KYE96VXRKBcZqLfONy3aE7dh76zKeqGzDzouztS7AtfEBqQoYwObsHjU0me46Ij7+gBVCZNB45yoQHXQY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HuK996iH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HuK996iH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32AB01F000E9; Thu, 2 Jul 2026 16:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783010219; bh=fh9NExQBY7F1nJGaeuIQ0RtZWiE/wi+2vhCzfoBzsf8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HuK996iHDnKm0ISKI1kN3glih/9EndCTyWZUtiSGU+i+ItXBl7vbNJi9REdvjbBWt BnAjsdVG1lIr46VdthSEbHjMSQDPpIyPbG6DGcCD7wPeoY6Fd6V+0ao7+KPaoKt3gp rfS5IqbXW8T0bVywx03SmUtE7a/98vrDfBgzj/mo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lord Ulf Henrik Holmberg , Leon Romanovsky Subject: [PATCH 6.12 027/204] RDMA/bnxt_re: zero shared page before exposing to userspace Date: Thu, 2 Jul 2026 18:18:04 +0200 Message-ID: <20260702155119.230212814@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155118.667618796@linuxfoundation.org> References: <20260702155118.667618796@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lord Ulf Henrik Holmberg commit f6b079629becfa977f9c51fe53ad2e6dcc55ef44 upstream. 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(). Fixes: 1ac5a4047975 ("RDMA/bnxt_re: Add bnxt_re RoCE driver") Signed-off-by: Lord Ulf Henrik Holmberg Link: https://patch.msgid.link/20260509084011.11971-1-pomzm67@gmail.com Signed-off-by: Leon Romanovsky Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/hw/bnxt_re/ib_verbs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c +++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c @@ -4231,7 +4231,7 @@ int bnxt_re_alloc_ucontext(struct ib_uco uctx->rdev = rdev; - uctx->shpg = (void *)__get_free_page(GFP_KERNEL); + uctx->shpg = (void *)get_zeroed_page(GFP_KERNEL); if (!uctx->shpg) { rc = -ENOMEM; goto fail;