Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755613Ab3CPLpP (ORCPT ); Sat, 16 Mar 2013 07:45:15 -0400 Received: from mail-bk0-f51.google.com ([209.85.214.51]:34572 "EHLO mail-bk0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753724Ab3CPLpN (ORCPT ); Sat, 16 Mar 2013 07:45:13 -0400 From: Sebastian Hesselbarth To: Sebastian Hesselbarth Cc: David Woodhouse , David Woodhouse , Jason Cooper , Thomas Petazzoni , Gregory Clement , Andrew Lunn , Ezequiel Garcia , Linus Walleij , Stephen Warren , Linux ARM Kernel , linux-kernel@vger.kernel.org Subject: [PATCH v3] pinctrl: mvebu: prevent walking off the end of group array Date: Sat, 16 Mar 2013 12:44:32 +0100 Message-Id: <1363434272-23172-1-git-send-email-sebastian.hesselbarth@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1363196884-20193-1-git-send-email-jason@lakedaemon.net> References: <1363196884-20193-1-git-send-email-jason@lakedaemon.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4200 Lines: 131 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 Signed-off-by: Sebastian Hesselbarth --- Jason, David, I tested the patch on Dove and fixed all remaining issues. Thomas, Gregory, Andrew should test on their platforms, too. Sebastian Changes from v2: - fix counting of available array space - fix return code handling Changes from v1: - correct typo (s/ nt / int /) I should've caught before sending. drivers/pinctrl/mvebu/pinctrl-mvebu.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) --- Cc: Jason Cooper Cc: David Woodhouse Cc: Sebastian Hesselbarth Cc: Thomas Petazzoni Cc: Gregory Clement Cc: Andrew Lunn Cc: Ezequiel Garcia Cc: Linus Walleij Cc: Stephen Warren Cc: Linux ARM Kernel Cc: linux-kernel@vger.kernel.org --- diff --git a/drivers/pinctrl/mvebu/pinctrl-mvebu.c b/drivers/pinctrl/mvebu/pinctrl-mvebu.c index c689c04..aa77fb7a 100644 --- a/drivers/pinctrl/mvebu/pinctrl-mvebu.c +++ b/drivers/pinctrl/mvebu/pinctrl-mvebu.c @@ -478,8 +478,12 @@ 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, int *funcsize, + const char *name) { + if (*funcsize <= 0) + return -EOVERFLOW; + while (funcs->num_groups) { /* function already there */ if (strcmp(funcs->name, name) == 0) { @@ -488,8 +492,12 @@ static int _add_function(struct mvebu_pinctrl_function *funcs, const char *name) } funcs++; } + + /* append new unique function */ funcs->name = name; funcs->num_groups = 1; + (*funcsize)--; + return 0; } @@ -497,12 +505,12 @@ static int mvebu_pinctrl_build_functions(struct platform_device *pdev, struct mvebu_pinctrl *pctl) { struct mvebu_pinctrl_function *funcs; - int num = 0; + int num = 0, funcsize = pctl->desc.npins; int n, s; /* we allocate functions for number of pins and hope - * there are less unique functions than pins available */ - funcs = devm_kzalloc(&pdev->dev, pctl->desc.npins * + * there are fewer unique functions than pins available */ + funcs = devm_kzalloc(&pdev->dev, funcsize * sizeof(struct mvebu_pinctrl_function), GFP_KERNEL); if (!funcs) return -ENOMEM; @@ -510,26 +518,27 @@ 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, &funcsize, + grp->settings[s].name); + if (ret == -EOVERFLOW) + dev_err(&pdev->dev, + "More functions than pins(%d)\n", + pctl->desc.npins); + if (ret < 0) 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; -- 1.7.10.4 -- 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/