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@xxxxxxxxxx> > --- > 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@xxxxxxxxxxxx/ > > /* Response consists only of incoming data */ > operation = gb_operation_create(connection, GB_I2C_TYPE_TRANSFER, > -- > 2.27.0 > -- Kees Cook
