2023-05-27 10:38:26

by Li Nan

Subject: [PATCH] md/bitmap: check input value with ULONG_MAX in timeout_store

From: Li Nan <[email protected]>

The type of timeout is unsigned long, but it is compared with 'LONG_MAX'
in timeout_store(), which lead to value within (LONG_MAX, ULONG_MAX.]/HZ
can't be set. Fix it by checking input value with ULONG_MAX.

Signed-off-by: Li Nan <[email protected]>
---
drivers/md/md-bitmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index bc8d7565171d..5fd9cba65be8 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -2460,7 +2460,7 @@ timeout_store(struct mddev *mddev, const char *buf, size_t len)
return rv;

/* just to make sure we don't overflow... */
- if (timeout >= LONG_MAX / HZ)
+ if (timeout >= ULONG_MAX / HZ)
return -EINVAL;

timeout = timeout * HZ / 10000;
--
2.31.1

2023-05-28 07:53:33

by Yu Kuai

Subject: Re: [PATCH] md/bitmap: check input value with ULONG_MAX in timeout_store

Hi,

?? 2023/05/27 18:18, [email protected] д??:
> From: Li Nan <[email protected]>
>
> The type of timeout is unsigned long, but it is compared with 'LONG_MAX'
> in timeout_store(), which lead to value within (LONG_MAX, ULONG_MAX.]/HZ
> can't be set. Fix it by checking input value with ULONG_MAX.
>

nak, because MAX_SCHEDULE_TIMEOUT is LONG_MAX, and LONG_MAX should be
enough for real use case.

Thanks,
Kuai
> Signed-off-by: Li Nan <[email protected]>
> ---
> drivers/md/md-bitmap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
> index bc8d7565171d..5fd9cba65be8 100644
> --- a/drivers/md/md-bitmap.c
> +++ b/drivers/md/md-bitmap.c
> @@ -2460,7 +2460,7 @@ timeout_store(struct mddev *mddev, const char *buf, size_t len)
> return rv;
>
> /* just to make sure we don't overflow... */
> - if (timeout >= LONG_MAX / HZ)
> + if (timeout >= ULONG_MAX / HZ)
> return -EINVAL;
>
> timeout = timeout * HZ / 10000;
>