On Tue, Apr 27, 2021 at 2:20 PM Colin Ian King <colin.king@xxxxxxxxxxxxx> wrote: > > On 27/04/2021 13:11, Andy Shevchenko wrote: > > On Tue, Apr 27, 2021 at 2:49 PM Colin King <colin.king@xxxxxxxxxxxxx> wrote: > >> > >> From: Colin Ian King <colin.king@xxxxxxxxxxxxx> > >> > >> The error return of config->id dereferences the kfree'd object config. > >> Fix this by using a temporary variable for the id to avoid this issue. > > > > Thanks! > > I'm wondering how I missed this... Nevertheless > > > > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > > > >> Addresses-Coverity: ("Read from pointer aftyer free") > > > > after > > > > Can that be fixed before applying rather me sending a V3? > No need, I'll add it and apply right away. Bartosz > >> Fixes: a49d14276ac4 ("gpio: sim: allocate IDA numbers earlier") > >> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> > >> --- > >> V2: Don't make id local to the if statement to improve coding style. > >> Thanks to Bartosz Golaszewski for this improvement suggestion. > >> --- > >> drivers/gpio/gpio-sim.c | 8 +++++--- > >> 1 file changed, 5 insertions(+), 3 deletions(-) > >> > >> diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c > >> index 2e2e6399e453..b21541c0b700 100644 > >> --- a/drivers/gpio/gpio-sim.c > >> +++ b/drivers/gpio/gpio-sim.c > >> @@ -744,20 +744,22 @@ static struct config_item * > >> gpio_sim_config_make_item(struct config_group *group, const char *name) > >> { > >> struct gpio_sim_chip_config *config; > >> + int id; > >> > >> config = kzalloc(sizeof(*config), GFP_KERNEL); > >> if (!config) > >> return ERR_PTR(-ENOMEM); > >> > >> - config->id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); > >> - if (config->id < 0) { > >> + id = ida_alloc(&gpio_sim_ida, GFP_KERNEL); > >> + if (id < 0) { > >> kfree(config); > >> - return ERR_PTR(config->id); > >> + return ERR_PTR(id); > >> } > >> > >> config_item_init_type_name(&config->item, name, > >> &gpio_sim_chip_config_type); > >> config->num_lines = 1; > >> + config->id = id; > >> mutex_init(&config->lock); > >> > >> return &config->item; > >> -- > >> 2.30.2 > >> > > > > >