Messages in this thread | | | Date | Thu, 15 Mar 2012 09:57:43 -0700 | From | Dirk Brandewie <> | Subject | Re: [patch] max17042_battery: fix a couple buffer overflows |
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On 03/15/2012 04:37 AM, Dan Carpenter wrote: > There are a couple issues here caused by confusion between sizeof() > and ARRAY_SIZE(). "table_size" should be the number of elements, but we > should allocate it with kcalloc() so that we allocate the correct number > of bytes. > > In max17042_init_model() we don't allocate enough space so we go past > the end of the array in max17042_read_model_data() and > max17042_model_data_compare(). > > In max17042_verify_model_lock() we allocate the right amount of space > but we call max17042_read_model_data() with the wrong number of elements > and also in the for loop we go past the end of the array. > > Signed-off-by: Dan Carpenter<dan.carpenter@oracle.com>
Acked-by: Dirk Brandewie <dirk.brandewie@intel.com>
> --- > I don't have this hardware. The original code is clearly buggy, but I > can't test that my fix is correct. Please review carefully. > > diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c > index e36763a..f8cd48c 100644 > --- a/drivers/power/max17042_battery.c > +++ b/drivers/power/max17042_battery.c > @@ -328,11 +328,10 @@ static inline int max17042_model_data_compare(struct max17042_chip *chip, > static int max17042_init_model(struct max17042_chip *chip) > { > int ret; > - int table_size = > - sizeof(chip->pdata->config_data->cell_char_tbl)/sizeof(u16); > + int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl); > u16 *temp_data; > > - temp_data = kzalloc(table_size, GFP_KERNEL); > + temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL); > if (!temp_data) > return -ENOMEM; > > @@ -357,12 +356,11 @@ static int max17042_init_model(struct max17042_chip *chip) > static int max17042_verify_model_lock(struct max17042_chip *chip) > { > int i; > - int table_size = > - sizeof(chip->pdata->config_data->cell_char_tbl); > + int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl); > u16 *temp_data; > int ret = 0; > > - temp_data = kzalloc(table_size, GFP_KERNEL); > + temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL); > if (!temp_data) > return -ENOMEM; >
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