2024-03-15 11:48:19

by Russell King (Oracle)

Subject: [PATCH] clkdev: report over-sized strings when creating clkdev entries

Report an error when an attempt to register a clkdev entry results in a
truncated string so the problem can be easily spotted.

Reported by: Duanqiang Wen <[email protected]>
Signed-off-by: Russell King (Oracle) <[email protected]>
---
drivers/clk/clkdev.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index ee37d0be6877..3146f26ab997 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -158,6 +158,10 @@ vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
va_list ap)
{
struct clk_lookup_alloc *cla;
+ struct va_format fmt;
+ const char *failure;
+ size_t max_size;
+ ssize_t res;

cla = kzalloc(sizeof(*cla), GFP_KERNEL);
if (!cla)
@@ -165,16 +169,34 @@ vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,

cla->cl.clk_hw = hw;
if (con_id) {
- strscpy(cla->con_id, con_id, sizeof(cla->con_id));
+ res = strscpy(cla->con_id, con_id, sizeof(cla->con_id));
+ if (res < 0) {
+ max_size = sizeof(cla->con_id);
+ failure = "connection";
+ goto fail;
+ }
cla->cl.con_id = cla->con_id;
}

if (dev_fmt) {
- vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
+ res = vsnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
+ if (res >= sizeof(cla->dev_id)) {
+ max_size = sizeof(cla->dev_id);
+ failure = "device";
+ goto fail;
+ }
cla->cl.dev_id = cla->dev_id;
}

return &cla->cl;
+
+fail:
+ fmt.fmt = dev_fmt;
+ fmt.va = &ap;
+ pr_err("%pV:%s: %s ID is greater than %zu\n",
+ &fmt, con_id, failure, max_size);
+ kfree(cla);
+ return NULL;
}

static struct clk_lookup *
--
2.30.2

2024-04-08 03:48:54

by Stephen Boyd

Subject: Re: [PATCH] clkdev: report over-sized strings when creating clkdev entries

Quoting Russell King (Oracle) (2024-03-15 04:47:55)
> Report an error when an attempt to register a clkdev entry results in a
> truncated string so the problem can be easily spotted.
>
> Reported by: Duanqiang Wen <[email protected]>
> Signed-off-by: Russell King (Oracle) <[email protected]>
> ---

Russell, are you taking this through your tree? I took the last one
because it was small and you reviewed it instead of applied it. If
you're taking it please add:

Reviewed-by: Stephen Boyd <[email protected]>