6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alessandro Carminati <alessandro.carminati@xxxxxxxxx>
commit ceb87a361d0b079ecbc7d2831618c19087f304a9 upstream.
In the possible_parent_show function, ensure proper handling of the return
value from of_clk_get_parent_name to prevent potential issues arising from
a NULL return.
The current implementation invokes seq_puts directly on the result of
of_clk_get_parent_name without verifying the return value, which can lead
to kernel panic if the function returns NULL.
This patch addresses the concern by introducing a check on the return
value of of_clk_get_parent_name. If the return value is not NULL, the
function proceeds to call seq_puts, providing the returned value as
argument.
However, if of_clk_get_parent_name returns NULL, the function provides a
static string as argument, avoiding the panic.
Fixes: 1ccc0ddf046a ("clk: Use seq_puts() in possible_parent_show()")
Reported-by: Philip Daly <pdaly@xxxxxxxxxx>
Signed-off-by: Alessandro Carminati (Red Hat) <alessandro.carminati@xxxxxxxxx>
Link: https://lore.kernel.org/r/20230921073217.572151-1-alessandro.carminati@xxxxxxxxx
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/clk/clk.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3340,6 +3340,7 @@ static void possible_parent_show(struct
unsigned int i, char terminator)
{
struct clk_core *parent;
+ const char *name = NULL;
/*
* Go through the following options to fetch a parent's name.
@@ -3354,18 +3355,20 @@ static void possible_parent_show(struct
* registered (yet).
*/
parent = clk_core_get_parent_by_index(core, i);
- if (parent)
+ if (parent) {
seq_puts(s, parent->name);
- else if (core->parents[i].name)
+ } else if (core->parents[i].name) {
seq_puts(s, core->parents[i].name);
- else if (core->parents[i].fw_name)
+ } else if (core->parents[i].fw_name) {
seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
- else if (core->parents[i].index >= 0)
- seq_puts(s,
- of_clk_get_parent_name(core->of_node,
- core->parents[i].index));
- else
- seq_puts(s, "(missing)");
+ } else {
+ if (core->parents[i].index >= 0)
+ name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
+ if (!name)
+ name = "(missing)";
+
+ seq_puts(s, name);
+ }
seq_putc(s, terminator);
}
