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 3D5983403FC; Thu, 2 Jul 2026 16:26:32 +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=1783009593; cv=none; b=WgOI0hoA78wL8DHmEcjdrZEeakUELI1X8AnqkPbfb1MvzDYofXM3ETJHDbPFSOTURFp0ml5EBcT0kprQbFb6YORDYDgtaP1Wi57IJTrB8NkUdoMydmR8IEIfRWbIUNOkwAaxRwyJf34CtIFDP7fcg/h/ItD87DH4WJRYwZDikG0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783009593; c=relaxed/simple; bh=Bac/BAqy/ENIIHmSGttCixWk/3zhoWQflFA7nH4ITrI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qoENXdI2pWoC3oB6EST09K88vTn06SrcROZinb6SFt7OSV31+s6E1rjtjKacrVOwJ/tZuMINDt/QrT74nTPj+xtrrVxgOTlgdA+r4ktibN5/yykjm5QnV+9qjS17iK+7tRQOnd6CFLRDyaLDMMGoeFW5+INdzZ+ACtzj/UZkeVk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rB61b9lv; 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="rB61b9lv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BC131F000E9; Thu, 2 Jul 2026 16:26:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783009592; bh=yv6tyF2PJFEdRuvWno2wOF6IAqJ485YArgOw2NTkERE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rB61b9lvg1UkpeR4My796VsH40GCbBQ6idibuDXEu4ISJIjfUXdedy6BFSGC9u1f5 gya1qFbTJVjL4Uae7empTwH+k4ijqXpz0Bsz2ek2sHTns4BdqD8MmUJwqbJ9HJ7iND M/ixHh1nM/aXYi2WhdqFyrj6uiuPKF+fm8wlY+Sw= 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 5.15 14/95] RDMA/bnxt_re: zero shared page before exposing to userspace Date: Thu, 2 Jul 2026 18:19:17 +0200 Message-ID: <20260702155109.506137802@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155109.196223802@linuxfoundation.org> References: <20260702155109.196223802@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 5.15-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 @@ -3864,7 +3864,7 @@ 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;