Messages in this thread |  | | Date | Tue, 17 Feb 2015 11:58:29 -0500 | From | Rhyland Klein <> | Subject | Re: [PATCH] clk: check for invalid parent index of orphans in __clk_init() |
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On 2/15/2015 7:33 AM, Mans Rullgard wrote: > If a mux clock is initialised (by hardware or firmware) with an > invalid parent, its ->get_parent() can return an out of range > index. For example, the generic mux clock attempts to return > -EINVAL, which due to the u8 return type ends up a rather large > number. Using this index with the parent_names[] array results > in an invalid pointer and (usually) a crash in the following > strcmp(). > > This patch adds a check for the parent index being in range, > ignoring clocks reporting invalid values. > > Signed-off-by: Mans Rullgard <mans@mansr.com> > Cc: Rhyland Klein <rklein@nvidia.com> > --- > drivers/clk/clk.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index d48ac71..bc0662b 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -1950,7 +1950,8 @@ int __clk_init(struct device *dev, struct clk *clk) > hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { > if (orphan->num_parents && orphan->ops->get_parent) { > i = orphan->ops->get_parent(orphan->hw); > - if (!strcmp(clk->name, orphan->parent_names[i])) > + if (i >= 0 && i < orphan->num_parents && > + !strcmp(clk->name, orphan->parent_names[i])) > __clk_reparent(orphan, clk); > continue; > } >
This works for me and is less invasive than the original patch series.
Tested-by: Rhyland Klein <rklein@nvidia.com>
-rhyland
-- nvpublic
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