Re: [PATCH v2 1/1] fs/squashfs: avoid illegal free() in sqfs_opendir()

[Joao Marcos Costa <joaomarcos.costa@bootlin.com>]

Hello,

On 4/14/25 15:19, Heinrich Schuchardt wrote:
> * Use calloc() to allocate token_list. This avoids an illegal free if
>    sqfs_tokenize() fails.
> * Do not iterate over token_list if it has not been allocated.
> 
> Addresses-Coverity-ID: 510453:  Null pointer dereferences  (FORWARD_NULL)
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
> v2:
> 	Fix typo in subject line
> ---
>   fs/squashfs/sqfs.c | 10 ++++++----
>   1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
> index 7c364686f14..2dcdd60f683 100644
> --- a/fs/squashfs/sqfs.c
> +++ b/fs/squashfs/sqfs.c
> @@ -949,7 +949,7 @@ static int sqfs_opendir_nest(const char *filename, struct fs_dir_stream **dirsp)
>   		goto out;
>   	}
>   
> -	token_list = malloc(token_count * sizeof(char *));
> +	token_list = calloc(token_count, sizeof(char *));
>   	if (!token_list) {
>   		ret = -EINVAL;
>   		goto out;
> @@ -987,9 +987,11 @@ static int sqfs_opendir_nest(const char *filename, struct fs_dir_stream **dirsp)
>   	*dirsp = (struct fs_dir_stream *)dirs;
>   
>   out:
> -	for (j = 0; j < token_count; j++)
> -		free(token_list[j]);
> -	free(token_list);
> +	if (token_list) {
> +		for (j = 0; j < token_count; j++)
> +			free(token_list[j]);
> +		free(token_list);
> +	}
>   	free(pos_list);
>   	free(path);
>   	if (ret) {

Reviewed-by: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
-- 
Best regards,
João Marcos Costa