diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index f6371dfa1f89..a3229add4455 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -426,18 +426,30 @@ __sigqueue_alloc(int sig, struct task_struct *t, gfp_t gfp_flags, rcu_read_lock(); ucounts = task_ucounts(t); sigpending = inc_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING, 1); - if (sigpending == 1) - ucounts = get_ucounts(ucounts); + switch (sigpending) { + case 1: + if (likely(get_ucounts(ucounts))) + break; + fallthrough; + case LONG_MAX: + /* + * we need to decrease the ucount in the userns tree on any + * failure to avoid counts leaking. + */ + dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING, 1); + rcu_read_unlock(); + return NULL; + } rcu_read_unlock(); - if (override_rlimit || (sigpending < LONG_MAX && sigpending <= task_rlimit(t, RLIMIT_SIGPENDING))) { + if (override_rlimit || likely(sigpending <= task_rlimit(t, RLIMIT_SIGPENDING))) { q = kmem_cache_alloc(sigqueue_cachep, gfp_flags); } else { print_dropped_signal(sig); } if (unlikely(q == NULL)) { - if (ucounts && dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING, 1)) + if (dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_SIGPENDING, 1)) put_ucounts(ucounts); } else { INIT_LIST_HEAD(&q->list); |