2022-01-26 13:03:47

by Gustavo A. R. Silva

Subject: [PATCH][next] comedi: das16: Use struct_size() helper in comedi_alloc_spriv()

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worst scenario, could lead to heap overflows.

Also, address the following sparse warnings:
drivers/comedi/drivers/das16.c:964:45: warning: using sizeof on a flexible structure
drivers/comedi/drivers/das16.c:998:45: warning: using sizeof on a flexible structure

Link: https://github.com/KSPP/linux/issues/174
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/comedi/drivers/das16.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/comedi/drivers/das16.c b/drivers/comedi/drivers/das16.c
index 937a69ce0977..728dc02156c8 100644
--- a/drivers/comedi/drivers/das16.c
+++ b/drivers/comedi/drivers/das16.c
@@ -961,7 +961,7 @@ static const struct comedi_lrange *das16_ai_range(struct comedi_device *dev,

/* allocate single-range range table */
lrange = comedi_alloc_spriv(s,
- sizeof(*lrange) + sizeof(*krange));
+ struct_size(lrange, range, 1));
if (!lrange)
return &range_unknown;

@@ -995,7 +995,7 @@ static const struct comedi_lrange *das16_ao_range(struct comedi_device *dev,

/* allocate single-range range table */
lrange = comedi_alloc_spriv(s,
- sizeof(*lrange) + sizeof(*krange));
+ struct_size(lrange, range, 1));
if (!lrange)
return &range_unknown;

--
2.27.0

2022-01-26 21:14:49

by Ian Abbott

Subject: Re: [PATCH][next] comedi: das16: Use struct_size() helper in comedi_alloc_spriv()

On 25/01/2022 23:25, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version,
> in order to avoid any potential type mistakes or integer overflows that,
> in the worst scenario, could lead to heap overflows.
>
> Also, address the following sparse warnings:
> drivers/comedi/drivers/das16.c:964:45: warning: using sizeof on a flexible structure
> drivers/comedi/drivers/das16.c:998:45: warning: using sizeof on a flexible structure
>
> Link: https://github.com/KSPP/linux/issues/174
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> drivers/comedi/drivers/das16.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/comedi/drivers/das16.c b/drivers/comedi/drivers/das16.c
> index 937a69ce0977..728dc02156c8 100644
> --- a/drivers/comedi/drivers/das16.c
> +++ b/drivers/comedi/drivers/das16.c
> @@ -961,7 +961,7 @@ static const struct comedi_lrange *das16_ai_range(struct comedi_device *dev,
>
> /* allocate single-range range table */
> lrange = comedi_alloc_spriv(s,
> - sizeof(*lrange) + sizeof(*krange));
> + struct_size(lrange, range, 1));
> if (!lrange)
> return &range_unknown;
>
> @@ -995,7 +995,7 @@ static const struct comedi_lrange *das16_ao_range(struct comedi_device *dev,
>
> /* allocate single-range range table */
> lrange = comedi_alloc_spriv(s,
> - sizeof(*lrange) + sizeof(*krange));
> + struct_size(lrange, range, 1));
> if (!lrange)
> return &range_unknown;
>

Looks like a nice tidy-up, thanks!

Reviewed-by: Ian Abbott <[email protected]>

(Note, I do not have anywhere to commit it, personally.)

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