Re: [PATCH] auxdisplay: ht16k33: don't access uninitialized data
On Tue, 28 Mar 2017 12:11:49 +0200 Arnd Bergmannwrote: > gcc-7.0.1 points out that we copy uninitialized data from the stack > into a per-device structure: > > drivers/auxdisplay/ht16k33.c: In function 'ht16k33_keypad_irq_thread': > arch/x86/include/asm/string_32.h:78:16: error: 'new_state' may be used > uninitialized in this function [-Werror=maybe-uninitialized] > arch/x86/include/asm/string_32.h:79:22: error: '*((void *)_state+4)' may > be used uninitialized in this function [-Werror=maybe-uninitialized] > > The access is harmless because we never read the data, but we are better > off not doing this, so this changes the code to only copy the data > that was actually initialized. To make sure we don't overflow the > stack with an incorrect DT, we also need to add a sanity checkin the > probe function. > > Signed-off-by: Arnd Bergmann Reviewed-by: Robin van der Gracht > --- > drivers/auxdisplay/ht16k33.c | 8 +++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c > index f66b45b235b0..ba6370974574 100644 > --- a/drivers/auxdisplay/ht16k33.c > +++ b/drivers/auxdisplay/ht16k33.c > @@ -278,7 +278,7 @@ static bool ht16k33_keypad_scan(struct ht16k33_keypad > *keypad) > } > } > input_sync(keypad->dev); > - memcpy(keypad->last_key_state, new_state, sizeof(new_state)); > + memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols); > > return pressed; > } > @@ -353,6 +353,12 @@ static int ht16k33_keypad_probe(struct i2c_client > *client, > err = matrix_keypad_parse_of_params(>dev, , ); > if (err) > return err; > + if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS || > + cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) { > + dev_err(>dev, "%u rows or %u cols out of range in DT\n", > + rows, cols); > + return -ERANGE; > + } > > keypad->rows = rows; > keypad->cols = cols;
Re: [PATCH] auxdisplay: ht16k33: don't access uninitialized data
On Tue, 28 Mar 2017 12:11:49 +0200 Arnd Bergmann wrote: > gcc-7.0.1 points out that we copy uninitialized data from the stack > into a per-device structure: > > drivers/auxdisplay/ht16k33.c: In function 'ht16k33_keypad_irq_thread': > arch/x86/include/asm/string_32.h:78:16: error: 'new_state' may be used > uninitialized in this function [-Werror=maybe-uninitialized] > arch/x86/include/asm/string_32.h:79:22: error: '*((void *)_state+4)' may > be used uninitialized in this function [-Werror=maybe-uninitialized] > > The access is harmless because we never read the data, but we are better > off not doing this, so this changes the code to only copy the data > that was actually initialized. To make sure we don't overflow the > stack with an incorrect DT, we also need to add a sanity checkin the > probe function. > > Signed-off-by: Arnd Bergmann Reviewed-by: Robin van der Gracht > --- > drivers/auxdisplay/ht16k33.c | 8 +++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c > index f66b45b235b0..ba6370974574 100644 > --- a/drivers/auxdisplay/ht16k33.c > +++ b/drivers/auxdisplay/ht16k33.c > @@ -278,7 +278,7 @@ static bool ht16k33_keypad_scan(struct ht16k33_keypad > *keypad) > } > } > input_sync(keypad->dev); > - memcpy(keypad->last_key_state, new_state, sizeof(new_state)); > + memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols); > > return pressed; > } > @@ -353,6 +353,12 @@ static int ht16k33_keypad_probe(struct i2c_client > *client, > err = matrix_keypad_parse_of_params(>dev, , ); > if (err) > return err; > + if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS || > + cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) { > + dev_err(>dev, "%u rows or %u cols out of range in DT\n", > + rows, cols); > + return -ERANGE; > + } > > keypad->rows = rows; > keypad->cols = cols;
Re: [PATCH] auxdisplay: ht16k33: don't access uninitialized data
On Tue, Mar 28, 2017 at 12:11:49PM +0200, Arnd Bergmann wrote: > gcc-7.0.1 points out that we copy uninitialized data from the stack > into a per-device structure: > > drivers/auxdisplay/ht16k33.c: In function 'ht16k33_keypad_irq_thread': > arch/x86/include/asm/string_32.h:78:16: error: 'new_state' may be used > uninitialized in this function [-Werror=maybe-uninitialized] > arch/x86/include/asm/string_32.h:79:22: error: '*((void *)_state+4)' may > be used uninitialized in this function [-Werror=maybe-uninitialized] > > The access is harmless because we never read the data, but we are better > off not doing this, so this changes the code to only copy the data > that was actually initialized. To make sure we don't overflow the > stack with an incorrect DT, we also need to add a sanity checkin the > probe function. > > Signed-off-by: Arnd BergmannReviewed-by: Dmitry Torokhov > --- > drivers/auxdisplay/ht16k33.c | 8 +++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c > index f66b45b235b0..ba6370974574 100644 > --- a/drivers/auxdisplay/ht16k33.c > +++ b/drivers/auxdisplay/ht16k33.c > @@ -278,7 +278,7 @@ static bool ht16k33_keypad_scan(struct ht16k33_keypad > *keypad) > } > } > input_sync(keypad->dev); > - memcpy(keypad->last_key_state, new_state, sizeof(new_state)); > + memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols); > > return pressed; > } > @@ -353,6 +353,12 @@ static int ht16k33_keypad_probe(struct i2c_client > *client, > err = matrix_keypad_parse_of_params(>dev, , ); > if (err) > return err; > + if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS || > + cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) { > + dev_err(>dev, "%u rows or %u cols out of range in DT\n", > + rows, cols); > + return -ERANGE; > + } > > keypad->rows = rows; > keypad->cols = cols; > -- > 2.9.0 > -- Dmitry
Re: [PATCH] auxdisplay: ht16k33: don't access uninitialized data
On Tue, Mar 28, 2017 at 12:11:49PM +0200, Arnd Bergmann wrote: > gcc-7.0.1 points out that we copy uninitialized data from the stack > into a per-device structure: > > drivers/auxdisplay/ht16k33.c: In function 'ht16k33_keypad_irq_thread': > arch/x86/include/asm/string_32.h:78:16: error: 'new_state' may be used > uninitialized in this function [-Werror=maybe-uninitialized] > arch/x86/include/asm/string_32.h:79:22: error: '*((void *)_state+4)' may > be used uninitialized in this function [-Werror=maybe-uninitialized] > > The access is harmless because we never read the data, but we are better > off not doing this, so this changes the code to only copy the data > that was actually initialized. To make sure we don't overflow the > stack with an incorrect DT, we also need to add a sanity checkin the > probe function. > > Signed-off-by: Arnd Bergmann Reviewed-by: Dmitry Torokhov > --- > drivers/auxdisplay/ht16k33.c | 8 +++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c > index f66b45b235b0..ba6370974574 100644 > --- a/drivers/auxdisplay/ht16k33.c > +++ b/drivers/auxdisplay/ht16k33.c > @@ -278,7 +278,7 @@ static bool ht16k33_keypad_scan(struct ht16k33_keypad > *keypad) > } > } > input_sync(keypad->dev); > - memcpy(keypad->last_key_state, new_state, sizeof(new_state)); > + memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols); > > return pressed; > } > @@ -353,6 +353,12 @@ static int ht16k33_keypad_probe(struct i2c_client > *client, > err = matrix_keypad_parse_of_params(>dev, , ); > if (err) > return err; > + if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS || > + cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) { > + dev_err(>dev, "%u rows or %u cols out of range in DT\n", > + rows, cols); > + return -ERANGE; > + } > > keypad->rows = rows; > keypad->cols = cols; > -- > 2.9.0 > -- Dmitry
[PATCH] auxdisplay: ht16k33: don't access uninitialized data
gcc-7.0.1 points out that we copy uninitialized data from the stack into a per-device structure: drivers/auxdisplay/ht16k33.c: In function 'ht16k33_keypad_irq_thread': arch/x86/include/asm/string_32.h:78:16: error: 'new_state' may be used uninitialized in this function [-Werror=maybe-uninitialized] arch/x86/include/asm/string_32.h:79:22: error: '*((void *)_state+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized] The access is harmless because we never read the data, but we are better off not doing this, so this changes the code to only copy the data that was actually initialized. To make sure we don't overflow the stack with an incorrect DT, we also need to add a sanity checkin the probe function. Signed-off-by: Arnd Bergmann--- drivers/auxdisplay/ht16k33.c | 8 +++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c index f66b45b235b0..ba6370974574 100644 --- a/drivers/auxdisplay/ht16k33.c +++ b/drivers/auxdisplay/ht16k33.c @@ -278,7 +278,7 @@ static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad) } } input_sync(keypad->dev); - memcpy(keypad->last_key_state, new_state, sizeof(new_state)); + memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols); return pressed; } @@ -353,6 +353,12 @@ static int ht16k33_keypad_probe(struct i2c_client *client, err = matrix_keypad_parse_of_params(>dev, , ); if (err) return err; + if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS || + cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) { + dev_err(>dev, "%u rows or %u cols out of range in DT\n", + rows, cols); + return -ERANGE; + } keypad->rows = rows; keypad->cols = cols; -- 2.9.0
[PATCH] auxdisplay: ht16k33: don't access uninitialized data
gcc-7.0.1 points out that we copy uninitialized data from the stack into a per-device structure: drivers/auxdisplay/ht16k33.c: In function 'ht16k33_keypad_irq_thread': arch/x86/include/asm/string_32.h:78:16: error: 'new_state' may be used uninitialized in this function [-Werror=maybe-uninitialized] arch/x86/include/asm/string_32.h:79:22: error: '*((void *)_state+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized] The access is harmless because we never read the data, but we are better off not doing this, so this changes the code to only copy the data that was actually initialized. To make sure we don't overflow the stack with an incorrect DT, we also need to add a sanity checkin the probe function. Signed-off-by: Arnd Bergmann --- drivers/auxdisplay/ht16k33.c | 8 +++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c index f66b45b235b0..ba6370974574 100644 --- a/drivers/auxdisplay/ht16k33.c +++ b/drivers/auxdisplay/ht16k33.c @@ -278,7 +278,7 @@ static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad) } } input_sync(keypad->dev); - memcpy(keypad->last_key_state, new_state, sizeof(new_state)); + memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols); return pressed; } @@ -353,6 +353,12 @@ static int ht16k33_keypad_probe(struct i2c_client *client, err = matrix_keypad_parse_of_params(>dev, , ); if (err) return err; + if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS || + cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) { + dev_err(>dev, "%u rows or %u cols out of range in DT\n", + rows, cols); + return -ERANGE; + } keypad->rows = rows; keypad->cols = cols; -- 2.9.0