Messages in this thread Patch in this message | | | From | Colin King <> | Subject | [PATCH][next][V2] gpio: sim: Fix dereference of free'd pointer config | Date | Tue, 27 Apr 2021 12:49:50 +0100 |
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From: Colin Ian King <colin.king@canonical.com>
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.
Addresses-Coverity: ("Read from pointer aftyer free") Fixes: a49d14276ac4 ("gpio: sim: allocate IDA numbers earlier") Signed-off-by: Colin Ian King <colin.king@canonical.com> --- 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
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