[lkml]   [2015]   [Feb]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH] clk: check for invalid parent index of orphans in __clk_init()
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

This patch adds a check for the parent index being in range,
ignoring clocks reporting invalid values.

Signed-off-by: Mans Rullgard <>
Cc: Rhyland Klein <>
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);

 \ /
  Last update: 2015-02-15 13:41    [W:0.789 / U:2.260 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site