diff options
authorArnd Bergmann <arnd@arndb.de>2017-03-28 12:11:49 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-04-08 17:48:19 +0200
commite1f990c24d14a80dd9b16ea967c9b76dbba501a3 (patch)
parentc7c3f096eb5e721d8522ba060fa621ea906ef738 (diff)
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 *)&new_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 <arnd@arndb.de> Reviewed-by: Robin van der Gracht <robin@protonic.nl> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 7 insertions, 1 deletions
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)
- 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(&client->dev, &rows, &cols);
if (err)
return err;
+ if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
+ dev_err(&client->dev, "%u rows or %u cols out of range in DT\n",
+ rows, cols);
+ return -ERANGE;
+ }
keypad->rows = rows;
keypad->cols = cols;

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