On Thu, 10 Mar 2022, Miaohe Lin wrote:
> user_shm_lock forgets to set allowed to 0 when get_ucounts fails. So
> the later user_shm_unlock might do the extra dec_rlimit_ucounts. Fix
> this by resetting allowed to 0.
>
> Fixes: 5ed44a401ddf ("do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY")
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
NAK. user_shm_lock() remembers to declare "int allowed = 0" on entry.
> ---
> mm/mlock.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/mm/mlock.c b/mm/mlock.c
> index 29372c0eebe5..efd2dd2943de 100644
> --- a/mm/mlock.c
> +++ b/mm/mlock.c
> @@ -733,6 +733,7 @@ int user_shm_lock(size_t size, struct ucounts *ucounts)
> }
> if (!get_ucounts(ucounts)) {
> dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked);
> + allowed = 0;
> goto out;
> }
> allowed = 1;
> --
> 2.23.0
>
>
>
