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 24991456DF7 for ; Wed, 29 Jul 2026 09:47:10 +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=1785318431; cv=none; b=dsXJ6WqqvPp6M4/1GnbpfdIPMXu3G48n4Gux+HWwftxDJm2pVBMxRMZcUxeZZFapeiRHN2jDVaBFXKwYCnD2GeDjSJx+vr+nVf6jeHSVnsl+FOKkOK/eM4443cGpdm3aAXkowDzjHlFcpu+/7Wavg3Go3uhjrvilJacnCOv3xW0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785318431; c=relaxed/simple; bh=Fm/xFGtSPGaE0IMoR6LQMu5zv3g+os3SN9jUPowd2lI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bbKZ+kDkIoNRYjbQLPaq2oZL8fbW5Orz+6rkZlRperwRlYjiW2Oe+E3F0bGJMbxTMCAag6IrH2lvqcbSE6Y8Wmcuc38Pv3+xepgzpVhZiaTiT0ElRrxzHm0altMWOj10i/UTY1CmtrYWAe+oDm0VbT/N+VaO9mLIaL84+4FvDqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R9yZELYo; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R9yZELYo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D4051F00A3D; Wed, 29 Jul 2026 09:47:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785318430; bh=PtFVxdV5c8wJ3Mn3Sijk9T4Fd4GLwdCdA5vcuot4ZPk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=R9yZELYoBlLyFmfnHeWKvBKWwLmn/5fbdIAOigWbuvbt/Sk1cRyt8yxvZodYlBi6O lpqL/c6pp52/HOdaaDrBRjo1NUTnY4Vc0+iLrOqXM84raLJdT/y2neYtNqBAhUdgLK tPHBKzucUuKzNxD9CXNQfoufZCmojmmoEuYdzGUaj1t0mPwoGRi63Z9t0yiQn7Qk5W vPNhZ+BSvdBPww2iIrf7U4EcIxTjIuD8sdQ0ehOgIhtLDzO344pR6LFZmLlMEVuVI2 3UUFizYonOqD2O1AGZb786SkKDfFefDxNwCIsCLqUjtAV4hTTuYdqQHo/+5H5YoV1U nuCpKX5C1dW6A== From: srini@kernel.org To: gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, Rosen Penev , Srinivas Kandagatla Subject: [PATCH 12/14] nvmem: brcm_nvram: reject empty NVRAM partition Date: Wed, 29 Jul 2026 10:46:45 +0100 Message-ID: <20260729094647.111468-13-srini@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260729094647.111468-1-srini@kernel.org> References: <20260729094647.111468-1-srini@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Rosen Penev If the partition is completely erased (all padding bytes), the trimming loop reduces data_len to 0. devm_kzalloc(dev, 0, GFP_KERNEL) returns ZERO_SIZE_PTR ((void *)16), which is non-NULL and bypasses the NULL check. The subsequent cast of priv->data to struct brcm_nvram_header * and dereference of header->magic causes a page fault on address 0x10. Reject data_len smaller than the header before allocating. Assisted-by: opencode:big-pickle Signed-off-by: Rosen Penev Signed-off-by: Srinivas Kandagatla --- drivers/nvmem/brcm_nvram.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/nvmem/brcm_nvram.c b/drivers/nvmem/brcm_nvram.c index aaa6537798bf..c3b4282aa164 100644 --- a/drivers/nvmem/brcm_nvram.c +++ b/drivers/nvmem/brcm_nvram.c @@ -84,6 +84,11 @@ static int brcm_nvram_copy_data(struct brcm_nvram *priv, struct platform_device } WARN(priv->data_len > SZ_128K, "Unexpected (big) NVRAM size: %zu B\n", priv->data_len); + if (priv->data_len < sizeof(struct brcm_nvram_header)) { + dev_err(priv->dev, "NVRAM data too small (%zu)\n", priv->data_len); + return -EINVAL; + } + priv->data = devm_kzalloc(priv->dev, priv->data_len, GFP_KERNEL); if (!priv->data) return -ENOMEM; -- 2.53.0