On Tue, 31 May 2022 14:50:19 +0800
Wu Guanghao <wuguanghao3@xxxxxxxxxx> wrote:
> When free(super->buf) but not set super->buf = NULL, will be double free
>
> get_super_block
> err = load_and_parse_mpb
> load_imsm_mpb(.., s, ..)
> if (posix_memalign(&super->buf, MAX_SECTOR_SIZE,
> super->len) != 0) // true, super->buf != NULL if
> (posix_memalign(&super->migr_rec_buf, MAX_SECTOR_SIZE,); // false
> free(super->buf); //but super->buf not set NULL return 2;
>
> if err ! = 0
> if (s)
> free_imsm(s)
> __free_imsm(s)
> if (s)
> free(s->buf); //double free
>
> Signed-off-by: Wu Guanghao <wuguanghao3@xxxxxxxxxx>
> ---
> super-intel.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/super-intel.c b/super-intel.c
> index ba3bd41f..ef21ffba 100644
> --- a/super-intel.c
> +++ b/super-intel.c
> @@ -4452,7 +4452,6 @@ static int load_imsm_mpb(int fd, struct intel_super
> *super, char *devname) if (posix_memalign(&super->migr_rec_buf,
> MAX_SECTOR_SIZE, MIGR_REC_BUF_SECTORS*MAX_SECTOR_SIZE) != 0) {
> pr_err("could not allocate migr_rec buffer\n");
> - free(super->buf);
> return 2;
> }
> super->clean_migration_record_by_mdmon = 0;
On error, we should possibly clean-up ourselves so I would expect from
load_imsm_mpb() to free super->buf in case when error occurs and set it
to NULL, especially that __free_imsm handles it.
Thanks,
Mariusz
