* [PATCH][next] staging: greybus: i2c: Use struct_size() helper in gb_i2c_operation_create()
@ 2022-01-21 22:22 Gustavo A. R. Silva
2022-01-24 20:19 ` Kees Cook
0 siblings, 1 reply; 5+ messages in thread
From: Gustavo A. R. Silva @ 2022-01-21 22:22 UTC (permalink / raw)
To: Viresh Kumar, Johan Hovold, Alex Elder, Greg Kroah-Hartman
Cc: greybus-dev, linux-staging, linux-kernel, Gustavo A. R. Silva,
linux-hardening
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/staging/greybus/i2c.c:111:24: warning: using sizeof on a flexible structure
Link: https://github.com/KSPP/linux/issues/174
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/staging/greybus/i2c.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/staging/greybus/i2c.c b/drivers/staging/greybus/i2c.c
index de2f6516da09..9dfc6791c20e 100644
--- a/drivers/staging/greybus/i2c.c
+++ b/drivers/staging/greybus/i2c.c
@@ -108,9 +108,7 @@ gb_i2c_operation_create(struct gb_connection *connection,
else
data_out_size += (u32)msg->len;
- request_size = sizeof(*request);
- request_size += msg_count * sizeof(*op);
- request_size += data_out_size;
+ request_size = struct_size(request, ops, msg_count) + data_out_size;
/* Response consists only of incoming data */
operation = gb_operation_create(connection, GB_I2C_TYPE_TRANSFER,
--
2.27.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH][next] staging: greybus: i2c: Use struct_size() helper in gb_i2c_operation_create()
2022-01-21 22:22 [PATCH][next] staging: greybus: i2c: Use struct_size() helper in gb_i2c_operation_create() Gustavo A. R. Silva
@ 2022-01-24 20:19 ` Kees Cook
2022-01-24 20:42 ` Gustavo A. R. Silva
2022-01-26 10:54 ` Dan Carpenter
0 siblings, 2 replies; 5+ messages in thread
From: Kees Cook @ 2022-01-24 20:19 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Viresh Kumar, Johan Hovold, Alex Elder, Greg Kroah-Hartman,
greybus-dev, linux-staging, linux-kernel, linux-hardening
On Fri, Jan 21, 2022 at 04:22:50PM -0600, 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/staging/greybus/i2c.c:111:24: warning: using sizeof on a flexible structure
>
> Link: https://github.com/KSPP/linux/issues/174
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> drivers/staging/greybus/i2c.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/staging/greybus/i2c.c b/drivers/staging/greybus/i2c.c
> index de2f6516da09..9dfc6791c20e 100644
> --- a/drivers/staging/greybus/i2c.c
> +++ b/drivers/staging/greybus/i2c.c
> @@ -108,9 +108,7 @@ gb_i2c_operation_create(struct gb_connection *connection,
> else
> data_out_size += (u32)msg->len;
>
> - request_size = sizeof(*request);
> - request_size += msg_count * sizeof(*op);
> - request_size += data_out_size;
> + request_size = struct_size(request, ops, msg_count) + data_out_size;
This could still overflow if struct_size() returns SIZE_MAX. Perhaps:
if (check_add_overflow(struct_size(request, ops, msg_count),
data_out_size, &request_size))
request_size = SIZE_MAX;
I should brush off the saturating arithmetic helpers series:
https://lore.kernel.org/all/20210920180853.1825195-1-keescook@chromium.org/
>
> /* Response consists only of incoming data */
> operation = gb_operation_create(connection, GB_I2C_TYPE_TRANSFER,
> --
> 2.27.0
>
--
Kees Cook
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH][next] staging: greybus: i2c: Use struct_size() helper in gb_i2c_operation_create()
2022-01-24 20:19 ` Kees Cook
@ 2022-01-24 20:42 ` Gustavo A. R. Silva
2022-01-26 10:54 ` Dan Carpenter
1 sibling, 0 replies; 5+ messages in thread
From: Gustavo A. R. Silva @ 2022-01-24 20:42 UTC (permalink / raw)
To: Kees Cook
Cc: Viresh Kumar, Johan Hovold, Alex Elder, Greg Kroah-Hartman,
greybus-dev, linux-staging, linux-kernel, linux-hardening
On Mon, Jan 24, 2022 at 12:19:03PM -0800, Kees Cook wrote:
> On Fri, Jan 21, 2022 at 04:22:50PM -0600, 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/staging/greybus/i2c.c:111:24: warning: using sizeof on a flexible structure
> >
> > Link: https://github.com/KSPP/linux/issues/174
> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> > ---
> > drivers/staging/greybus/i2c.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/drivers/staging/greybus/i2c.c b/drivers/staging/greybus/i2c.c
> > index de2f6516da09..9dfc6791c20e 100644
> > --- a/drivers/staging/greybus/i2c.c
> > +++ b/drivers/staging/greybus/i2c.c
> > @@ -108,9 +108,7 @@ gb_i2c_operation_create(struct gb_connection *connection,
> > else
> > data_out_size += (u32)msg->len;
> >
> > - request_size = sizeof(*request);
> > - request_size += msg_count * sizeof(*op);
> > - request_size += data_out_size;
> > + request_size = struct_size(request, ops, msg_count) + data_out_size;
>
> This could still overflow if struct_size() returns SIZE_MAX. Perhaps:
uggh... I got too excited with all the new cases reported.
>
> if (check_add_overflow(struct_size(request, ops, msg_count),
> data_out_size, &request_size))
> request_size = SIZE_MAX;
Yep; I'll respin and include this change, thanks!
>
> I should brush off the saturating arithmetic helpers series:
> https://lore.kernel.org/all/20210920180853.1825195-1-keescook@chromium.org/
Yeah; those helpers are very much needed in many places we need to audit...
--
Gustavo
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH][next] staging: greybus: i2c: Use struct_size() helper in gb_i2c_operation_create()
2022-01-24 20:19 ` Kees Cook
2022-01-24 20:42 ` Gustavo A. R. Silva
@ 2022-01-26 10:54 ` Dan Carpenter
2022-01-27 10:05 ` Kees Cook
1 sibling, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2022-01-26 10:54 UTC (permalink / raw)
To: Kees Cook
Cc: Gustavo A. R. Silva, Viresh Kumar, Johan Hovold, Alex Elder,
Greg Kroah-Hartman, greybus-dev, linux-staging, linux-kernel,
linux-hardening
On Mon, Jan 24, 2022 at 12:19:03PM -0800, Kees Cook wrote:
> This could still overflow if struct_size() returns SIZE_MAX. Perhaps:
>
> if (check_add_overflow(struct_size(request, ops, msg_count),
> data_out_size, &request_size))
> request_size = SIZE_MAX;
>
> I should brush off the saturating arithmetic helpers series:
> https://lore.kernel.org/all/20210920180853.1825195-1-keescook@chromium.org/
Yes, please! Those seem like a million times easier to use.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH][next] staging: greybus: i2c: Use struct_size() helper in gb_i2c_operation_create()
2022-01-26 10:54 ` Dan Carpenter
@ 2022-01-27 10:05 ` Kees Cook
0 siblings, 0 replies; 5+ messages in thread
From: Kees Cook @ 2022-01-27 10:05 UTC (permalink / raw)
To: Dan Carpenter
Cc: Gustavo A. R. Silva, Viresh Kumar, Johan Hovold, Alex Elder,
Greg Kroah-Hartman, greybus-dev, linux-staging, linux-kernel,
linux-hardening
On Wed, Jan 26, 2022 at 01:54:04PM +0300, Dan Carpenter wrote:
> On Mon, Jan 24, 2022 at 12:19:03PM -0800, Kees Cook wrote:
> > This could still overflow if struct_size() returns SIZE_MAX. Perhaps:
> >
> > if (check_add_overflow(struct_size(request, ops, msg_count),
> > data_out_size, &request_size))
> > request_size = SIZE_MAX;
> >
> > I should brush off the saturating arithmetic helpers series:
> > https://lore.kernel.org/all/20210920180853.1825195-1-keescook@chromium.org/
>
> Yes, please! Those seem like a million times easier to use.
Here they are! :) Please review:
https://lore.kernel.org/lkml/20220124232342.3113350-1-keescook@chromium.org/
Thanks!
--
Kees Cook
^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-01-24 20:19 ` Kees Cook
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