From aaed651ff619993fb2101a22b32dd0664e54921b Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sat, 16 Mar 2013 12:44:32 +0100 Subject: [PATCH] pinctrl: mvebu: prevent walking off the end of group array 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 Acked-by: Jason Cooper Signed-off-by: Linus Walleij --- drivers/pinctrl/mvebu/pinctrl-mvebu.c | 33 +++++++++++++++++---------- 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/drivers/pinctrl/mvebu/pinctrl-mvebu.c b/drivers/pinctrl/mvebu/pinctrl-mvebu.c index 61149914882d..38d3b22e172d 100644 --- a/drivers/pinctrl/mvebu/pinctrl-mvebu.c +++ b/drivers/pinctrl/mvebu/pinctrl-mvebu.c @@ -478,8 +478,12 @@ static const 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; -- 2.20.1