Inside function hideep_nvm_unlock(), variable "unmask_code" could
be uninitialized if hideep_pgm_r_reg() returns error, however, it
is used in the later if statement after an "and" operation, which
is potentially unsafe.
Signed-off-by: Yizhuo <[email protected]>
---
drivers/input/touchscreen/hideep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/input/touchscreen/hideep.c
b/drivers/input/touchscreen/hideep.c
index ddad4a82a5e5..49b713ad4384 100644
--- a/drivers/input/touchscreen/hideep.c
+++ b/drivers/input/touchscreen/hideep.c
@@ -363,7 +363,7 @@ static int hideep_enter_pgm(struct hideep_ts *ts)
static void hideep_nvm_unlock(struct hideep_ts *ts)
{
- u32 unmask_code;
+ u32 unmask_code = 0;
hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_SFR_RPAGE);
hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
--
2.17.1
Hi Yizhuo,
On Tue, Jun 15, 2021 at 10:26:09AM -0700, Yizhuo Zhai wrote:
> Inside function hideep_nvm_unlock(), variable "unmask_code" could
> be uninitialized if hideep_pgm_r_reg() returns error, however, it
> is used in the later if statement after an "and" operation, which
> is potentially unsafe.
I do not think that simply initializing the variable makes the code
behave any better. If we want to fix this properly we need to check for
errors returned by hideep_pgm_r_reg() and hideep_pgm_w_reg() and exit
this function early, signalling the caller about errors.
>
> Signed-off-by: Yizhuo <[email protected]>
> ---
> drivers/input/touchscreen/hideep.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/input/touchscreen/hideep.c
> b/drivers/input/touchscreen/hideep.c
> index ddad4a82a5e5..49b713ad4384 100644
> --- a/drivers/input/touchscreen/hideep.c
> +++ b/drivers/input/touchscreen/hideep.c
> @@ -363,7 +363,7 @@ static int hideep_enter_pgm(struct hideep_ts *ts)
>
> static void hideep_nvm_unlock(struct hideep_ts *ts)
> {
> - u32 unmask_code;
> + u32 unmask_code = 0;
>
> hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_SFR_RPAGE);
> hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
> --
> 2.17.1
Thanks.
--
Dmitry
Hi Demitry:
Thanks for your quick response, following your advice, a careful way
is changing the return type of "hideep_nvm_unlock()" from void to
int, and its caller "hideep_program_nvm()" also needs to add the
return check.
If this sounds ok, I would go ahead to modify the patch accordingly.
On Tue, Jun 15, 2021 at 11:15 AM Dmitry Torokhov
<[email protected]> wrote:
>
> Hi Yizhuo,
>
> On Tue, Jun 15, 2021 at 10:26:09AM -0700, Yizhuo Zhai wrote:
> > Inside function hideep_nvm_unlock(), variable "unmask_code" could
> > be uninitialized if hideep_pgm_r_reg() returns error, however, it
> > is used in the later if statement after an "and" operation, which
> > is potentially unsafe.
>
> I do not think that simply initializing the variable makes the code
> behave any better. If we want to fix this properly we need to check for
> errors returned by hideep_pgm_r_reg() and hideep_pgm_w_reg() and exit
> this function early, signalling the caller about errors.
>
> >
> > Signed-off-by: Yizhuo <[email protected]>
> > ---
> > drivers/input/touchscreen/hideep.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/input/touchscreen/hideep.c
> > b/drivers/input/touchscreen/hideep.c
> > index ddad4a82a5e5..49b713ad4384 100644
> > --- a/drivers/input/touchscreen/hideep.c
> > +++ b/drivers/input/touchscreen/hideep.c
> > @@ -363,7 +363,7 @@ static int hideep_enter_pgm(struct hideep_ts *ts)
> >
> > static void hideep_nvm_unlock(struct hideep_ts *ts)
> > {
> > - u32 unmask_code;
> > + u32 unmask_code = 0;
> >
> > hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_SFR_RPAGE);
> > hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
> > --
> > 2.17.1
>
> Thanks.
>
> --
> Dmitry
--
Kind Regards,
Yizhuo Zhai
Computer Science, Graduate Student
University of California, Riverside
On Tue, Jun 15, 2021 at 11:57:36AM -0700, Yizhuo Zhai wrote:
> Hi Demitry:
>
> Thanks for your quick response, following your advice, a careful way
> is changing the return type of "hideep_nvm_unlock()" from void to
> int, and its caller "hideep_program_nvm()" also needs to add the
> return check.
>
> If this sounds ok, I would go ahead to modify the patch accordingly.
Yes, this sounds right.
>
> On Tue, Jun 15, 2021 at 11:15 AM Dmitry Torokhov
> <[email protected]> wrote:
> >
> > Hi Yizhuo,
> >
> > On Tue, Jun 15, 2021 at 10:26:09AM -0700, Yizhuo Zhai wrote:
> > > Inside function hideep_nvm_unlock(), variable "unmask_code" could
> > > be uninitialized if hideep_pgm_r_reg() returns error, however, it
> > > is used in the later if statement after an "and" operation, which
> > > is potentially unsafe.
> >
> > I do not think that simply initializing the variable makes the code
> > behave any better. If we want to fix this properly we need to check for
> > errors returned by hideep_pgm_r_reg() and hideep_pgm_w_reg() and exit
> > this function early, signalling the caller about errors.
> >
> > >
> > > Signed-off-by: Yizhuo <[email protected]>
> > > ---
> > > drivers/input/touchscreen/hideep.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/input/touchscreen/hideep.c
> > > b/drivers/input/touchscreen/hideep.c
> > > index ddad4a82a5e5..49b713ad4384 100644
> > > --- a/drivers/input/touchscreen/hideep.c
> > > +++ b/drivers/input/touchscreen/hideep.c
> > > @@ -363,7 +363,7 @@ static int hideep_enter_pgm(struct hideep_ts *ts)
> > >
> > > static void hideep_nvm_unlock(struct hideep_ts *ts)
> > > {
> > > - u32 unmask_code;
> > > + u32 unmask_code = 0;
> > >
> > > hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_SFR_RPAGE);
> > > hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
> > > --
> > > 2.17.1
> >
> > Thanks.
> >
> > --
> > Dmitry
>
>
>
> --
> Kind Regards,
>
> Yizhuo Zhai
>
> Computer Science, Graduate Student
> University of California, Riverside
--
Dmitry
On Wed, Jun 16, 2021 at 03:48:51PM -0700, Yizhuo Zhai wrote:
> Inside function hideep_nvm_unlock(), variable "unmask_code" could
> be uninitialized if hideep_pgm_r_reg() returns error, however, it
> is used in the later if statement after an "and" operation, which
> is potentially unsafe.
I think this is pretty sensible, but let's see if the original author
has some comments...
>
> Signed-off-by: Yizhuo <[email protected]>
> ---
> drivers/input/touchscreen/hideep.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/touchscreen/hideep.c
> b/drivers/input/touchscreen/hideep.c
> index ddad4a82a5e5..f860a815b603 100644
> --- a/drivers/input/touchscreen/hideep.c
> +++ b/drivers/input/touchscreen/hideep.c
> @@ -364,9 +364,13 @@ static int hideep_enter_pgm(struct hideep_ts *ts)
> static void hideep_nvm_unlock(struct hideep_ts *ts)
> {
> u32 unmask_code;
> + int ret;
>
> hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_SFR_RPAGE);
> - hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
> + ret = hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
> + if (ret)
> + return ret;
> +
> hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_DEFAULT_PAGE);
>
> /* make it unprotected code */
> @@ -462,7 +466,9 @@ static int hideep_program_nvm(struct hideep_ts *ts,
> u32 addr = 0;
> int error;
>
> - hideep_nvm_unlock(ts);
> + error = hideep_nvm_unlock(ts);
> + if (error)
> + return error;
>
> while (ucode_len > 0) {
> xfer_len = min_t(size_t, ucode_len, HIDEEP_NVM_PAGE_SIZE);
> --
> 2.17.1
--
Dmitry
On Sat, Jun 19, 2021 at 10:10:37PM -0700, Dmitry Torokhov wrote:
> On Wed, Jun 16, 2021 at 03:48:51PM -0700, Yizhuo Zhai wrote:
> > Inside function hideep_nvm_unlock(), variable "unmask_code" could
> > be uninitialized if hideep_pgm_r_reg() returns error, however, it
> > is used in the later if statement after an "and" operation, which
> > is potentially unsafe.
>
> I think this is pretty sensible, but let's see if the original author
> has some comments...
I guess not. Oh well...
Applied, thank you.
--
Dmitry
On Sat, Jun 19, 2021 at 10:26:40PM -0700, Dmitry Torokhov wrote:
> On Sat, Jun 19, 2021 at 10:10:37PM -0700, Dmitry Torokhov wrote:
> > On Wed, Jun 16, 2021 at 03:48:51PM -0700, Yizhuo Zhai wrote:
> > > Inside function hideep_nvm_unlock(), variable "unmask_code" could
> > > be uninitialized if hideep_pgm_r_reg() returns error, however, it
> > > is used in the later if statement after an "and" operation, which
> > > is potentially unsafe.
> >
> > I think this is pretty sensible, but let's see if the original author
> > has some comments...
>
> I guess not. Oh well...
>
> Applied, thank you.
Note that I had to make some changes to make it compile. Please next
time try building your changes before posting them,
Thanks.
--
Dmitry
Dimitry:
Sorry for the inconvenience, I would build the changes next time.
Thanks for your help : )
On Sat, Jun 19, 2021 at 10:35 PM Dmitry Torokhov
<[email protected]> wrote:
>
> On Sat, Jun 19, 2021 at 10:26:40PM -0700, Dmitry Torokhov wrote:
> > On Sat, Jun 19, 2021 at 10:10:37PM -0700, Dmitry Torokhov wrote:
> > > On Wed, Jun 16, 2021 at 03:48:51PM -0700, Yizhuo Zhai wrote:
> > > > Inside function hideep_nvm_unlock(), variable "unmask_code" could
> > > > be uninitialized if hideep_pgm_r_reg() returns error, however, it
> > > > is used in the later if statement after an "and" operation, which
> > > > is potentially unsafe.
> > >
> > > I think this is pretty sensible, but let's see if the original author
> > > has some comments...
> >
> > I guess not. Oh well...
> >
> > Applied, thank you.
>
> Note that I had to make some changes to make it compile. Please next
> time try building your changes before posting them,
>
> Thanks.
>
> --
> Dmitry
--
Kind Regards,
Yizhuo Zhai
Computer Science, Graduate Student
University of California, Riverside