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authorDavid Woodhouse <dwmw2@infradead.org>2013-03-16 12:44:32 +0100
committerLinus Walleij <linus.walleij@linaro.org>2013-03-27 23:36:17 +0100
commitaaed651ff619993fb2101a22b32dd0664e54921b (patch)
tree43d78fe1b6f8eb754005153bcc8d694198789ffc /drivers/pinctrl/mvebu
parent50cf7c8ab324de348990bb028ad9ed10872d527a (diff)
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 <David.Woodhouse@intel.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Acked-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl/mvebu')
-rw-r--r--drivers/pinctrl/mvebu/pinctrl-mvebu.c33
1 files 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;