From: David Woodhouse <dw...@infradead.org>
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.woodho...@intel.com>
Signed-off-by: Jason Cooper <ja...@lakedaemon.net>
---
Changes from v1:
- correct typo (s/ nt / int /) I should've caught before sending.
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..5db5fad 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, int 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
--
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