Messages in this thread Patch in this message | | | From | Alessandro Carminati <> | Subject | [PATCH] Sanitize possible_parent_show to Handle Return Value of of_clk_get_parent_name | Date | Tue, 22 Aug 2023 13:48:49 +0000 |
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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.
Reported-by: Philip Daly <pdaly@redhat.com> Signed-off-by: Alessandro Carminati (Red Hat) <alessandro.carminati@gmail.com> --- drivers/clk/clk.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index c249f9791ae8..ab999644e185 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -3416,6 +3416,7 @@ static void possible_parent_show(struct seq_file *s, struct clk_core *core, unsigned int i, char terminator) { struct clk_core *parent; + const char *tmp; /* * Go through the following options to fetch a parent's name. @@ -3436,12 +3437,12 @@ static void possible_parent_show(struct seq_file *s, struct clk_core *core, seq_puts(s, core->parents[i].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 + else if (core->parents[i].index >= 0) { + tmp = of_clk_get_parent_name(core->of_node, core->parents[i].index); + seq_puts(s, tmp ? tmp : "(none)"); + } else { seq_puts(s, "(missing)"); + } seq_putc(s, terminator); } -- 2.34.1
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