Return-path: Received: from wolverine01.qualcomm.com ([199.106.114.254]:60660 "EHLO wolverine01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932094AbcK1LtN (ORCPT ); Mon, 28 Nov 2016 06:49:13 -0500 From: Maya Erez To: Kalle Valo Cc: Maya Erez , linux-wireless@vger.kernel.org, wil6210@qca.qualcomm.com Subject: [PATCH 2/4] wil6210: validate wil_pmc_alloc parameters Date: Mon, 28 Nov 2016 13:49:01 +0200 Message-Id: <1480333743-7306-3-git-send-email-qca_merez@qca.qualcomm.com> (sfid-20161128_124917_832865_2918F1C7) In-Reply-To: <1480333743-7306-1-git-send-email-qca_merez@qca.qualcomm.com> References: <1480333743-7306-1-git-send-email-qca_merez@qca.qualcomm.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: num_descriptors and descriptor_size needs to be checked for: 1) not being negative values 2) no overflow occurs when these are multiplied together as done in wil_pmc_read. An overflow of two signed integers is undefined behavior. Signed-off-by: Maya Erez --- drivers/net/wireless/ath/wil6210/pmc.c | 55 ++++++++++++++++++++++++++++++---- 1 file changed, 49 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/ath/wil6210/pmc.c b/drivers/net/wireless/ath/wil6210/pmc.c index 5ca0307..b9faae0 100644 --- a/drivers/net/wireless/ath/wil6210/pmc.c +++ b/drivers/net/wireless/ath/wil6210/pmc.c @@ -54,6 +54,7 @@ void wil_pmc_alloc(struct wil6210_priv *wil, struct pmc_ctx *pmc = &wil->pmc; struct device *dev = wil_to_dev(wil); struct wmi_pmc_cmd pmc_cmd = {0}; + int last_cmd_err = -ENOMEM; mutex_lock(&pmc->lock); @@ -62,6 +63,29 @@ void wil_pmc_alloc(struct wil6210_priv *wil, wil_err(wil, "%s: ERROR pmc is already allocated\n", __func__); goto no_release_err; } + if ((num_descriptors <= 0) || (descriptor_size <= 0)) { + wil_err(wil, + "Invalid params num_descriptors(%d), descriptor_size(%d)\n", + num_descriptors, descriptor_size); + last_cmd_err = -EINVAL; + goto no_release_err; + } + + if (num_descriptors > (1 << WIL_RING_SIZE_ORDER_MAX)) { + wil_err(wil, + "num_descriptors(%d) exceeds max ring size %d\n", + num_descriptors, 1 << WIL_RING_SIZE_ORDER_MAX); + last_cmd_err = -EINVAL; + goto no_release_err; + } + + if (num_descriptors > INT_MAX / descriptor_size) { + wil_err(wil, + "Overflow in num_descriptors(%d)*descriptor_size(%d)\n", + num_descriptors, descriptor_size); + last_cmd_err = -EINVAL; + goto no_release_err; + } pmc->num_descriptors = num_descriptors; pmc->descriptor_size = descriptor_size; @@ -189,7 +213,7 @@ void wil_pmc_alloc(struct wil6210_priv *wil, pmc->descriptors = NULL; no_release_err: - pmc->last_cmd_status = -ENOMEM; + pmc->last_cmd_status = last_cmd_err; mutex_unlock(&pmc->lock); } @@ -295,7 +319,7 @@ ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count, size_t retval = 0; unsigned long long idx; loff_t offset; - size_t pmc_size = pmc->descriptor_size * pmc->num_descriptors; + size_t pmc_size; mutex_lock(&pmc->lock); @@ -306,6 +330,8 @@ ssize_t wil_pmc_read(struct file *filp, char __user *buf, size_t count, return -EPERM; } + pmc_size = pmc->descriptor_size * pmc->num_descriptors; + wil_dbg_misc(wil, "%s: size %u, pos %lld\n", __func__, (unsigned)count, *f_pos); @@ -345,7 +371,18 @@ loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence) loff_t newpos; struct wil6210_priv *wil = filp->private_data; struct pmc_ctx *pmc = &wil->pmc; - size_t pmc_size = pmc->descriptor_size * pmc->num_descriptors; + size_t pmc_size; + + mutex_lock(&pmc->lock); + + if (!wil_is_pmc_allocated(pmc)) { + wil_err(wil, "error, pmc is not allocated!\n"); + pmc->last_cmd_status = -EPERM; + mutex_unlock(&pmc->lock); + return -EPERM; + } + + pmc_size = pmc->descriptor_size * pmc->num_descriptors; switch (whence) { case 0: /* SEEK_SET */ @@ -361,15 +398,21 @@ loff_t wil_pmc_llseek(struct file *filp, loff_t off, int whence) break; default: /* can't happen */ - return -EINVAL; + newpos = -EINVAL; + goto out; } - if (newpos < 0) - return -EINVAL; + if (newpos < 0) { + newpos = -EINVAL; + goto out; + } if (newpos > pmc_size) newpos = pmc_size; filp->f_pos = newpos; +out: + mutex_unlock(&pmc->lock); + return newpos; } -- 1.9.1