Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933884Ab3CMRgN (ORCPT ); Wed, 13 Mar 2013 13:36:13 -0400 Received: from mho-04-ewr.mailhop.org ([204.13.248.74]:37172 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932881Ab3CMRgM (ORCPT ); Wed, 13 Mar 2013 13:36:12 -0400 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 72.84.113.162 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX19NG84xJvCB+OeTwCnSFGmhZp2lDqbVW1I= From: Jason Cooper To: David Woodhouse , Linus Walleij Cc: Sebastian Hesselbarth , Thomas Petazzoni , Stephen Warren , linux-kernel@vger.kernel.org, Gregory CLEMENT , Ezequiel Garcia , Linux ARM Kernel , David Woodhouse , Jason Cooper Subject: [PATCH] pinctrl: mvebu: prevent walking off the end of group array Date: Wed, 13 Mar 2013 17:35:55 +0000 Message-Id: <1363196155-1620-1-git-send-email-jason@lakedaemon.net> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1362872371.3690.106.camel@shinybook.infradead.org> References: <1362872371.3690.106.camel@shinybook.infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3103 Lines: 94 From: David Woodhouse While investigating (ab)use of krealloc, David found this bug. It's unlikely to occur, but now we detect the condition and error out appropriately. Signed-off-by: David Woodhouse Signed-off-by: Jason Cooper --- David, please double check that this is as you intended. I had to hand-jam it in due to some peculiarities on my side. drivers/pinctrl/mvebu/pinctrl-mvebu.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/pinctrl/mvebu/pinctrl-mvebu.c b/drivers/pinctrl/mvebu/pinctrl-mvebu.c index c689c04..8d8f175 100644 --- a/drivers/pinctrl/mvebu/pinctrl-mvebu.c +++ b/drivers/pinctrl/mvebu/pinctrl-mvebu.c @@ -478,16 +478,21 @@ static struct pinctrl_ops mvebu_pinctrl_ops = { .dt_free_map = mvebu_pinctrl_dt_free_map, }; -static int _add_function(struct mvebu_pinctrl_function *funcs, const char *name) +static int _add_function(struct mvebu_pinctrl_function *funcs, nt nr_funcs, + const char *name) { - while (funcs->num_groups) { + while (nr_funcs && funcs->num_groups) { /* function already there */ if (strcmp(funcs->name, name) == 0) { funcs->num_groups++; return -EEXIST; } funcs++; + nr_funcs--; } + if (!nr_funcs) + return -EOVERFLOW; + funcs->name = name; funcs->num_groups = 1; return 0; @@ -501,7 +506,7 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev, int n, s; /* we allocate functions for number of pins and hope - * there are less unique functions than pins available */ + * there are fewer unique functions than pins available */ funcs = devm_kzalloc(&pdev->dev, pctl->desc.npins * sizeof(struct mvebu_pinctrl_function), GFP_KERNEL); if (!funcs) @@ -510,26 +515,26 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev, for (n = 0; n < pctl->num_groups; n++) { struct mvebu_pinctrl_group *grp = &pctl->groups[n]; for (s = 0; s < grp->num_settings; s++) { + int ret; + /* skip unsupported settings on this variant */ if (pctl->variant && !(pctl->variant & grp->settings[s].variant)) continue; /* check for unique functions and count groups */ - if (_add_function(funcs, grp->settings[s].name)) + ret = _add_function(funcs, pctl->desc.npins, + grp->settings[s].name); + if (ret == -EOVERFLOW) + dev_err(&pdev->dev, + "More functions than pins(%d)\n", + pctl->desc.npins); continue; num++; } } - /* with the number of unique functions and it's groups known, - reallocate functions and assign group names */ - funcs = krealloc(funcs, num * sizeof(struct mvebu_pinctrl_function), - GFP_KERNEL); - if (!funcs) - return -ENOMEM; - pctl->num_functions = num; pctl->functions = funcs; -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/