If someone stores both a timer and a workqueue in a hash map, on free, we
would walk it twice.
Add a check in htab_free_malloced_timers_or_wq and free the timers
and workqueues if they are present.
Fixes: 246331e3f1ea ("bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps")
Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx>
---
kernel/bpf/hashtab.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 0179183c543a..20162ae741e9 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1515,7 +1515,7 @@ static void delete_all_elements(struct bpf_htab *htab)
migrate_enable();
}
-static void htab_free_malloced_timers_or_wq(struct bpf_htab *htab, bool is_timer)
+static void htab_free_malloced_timers_or_wq(struct bpf_htab *htab)
{
int i;
@@ -1527,10 +1527,10 @@ static void htab_free_malloced_timers_or_wq(struct bpf_htab *htab, bool is_timer
hlist_nulls_for_each_entry(l, n, head, hash_node) {
/* We only free timer on uref dropping to zero */
- if (is_timer)
+ if (btf_record_has_field(htab->map.record, BPF_TIMER))
bpf_obj_free_timer(htab->map.record,
l->key + round_up(htab->map.key_size, 8));
- else
+ if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE))
bpf_obj_free_workqueue(htab->map.record,
l->key + round_up(htab->map.key_size, 8));
}
@@ -1544,18 +1544,12 @@ static void htab_map_free_timers_and_wq(struct bpf_map *map)
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
/* We only free timer and workqueue on uref dropping to zero */
- if (btf_record_has_field(htab->map.record, BPF_TIMER)) {
+ if (btf_record_has_field(htab->map.record, BPF_TIMER | BPF_WORKQUEUE)) {
if (!htab_is_prealloc(htab))
- htab_free_malloced_timers_or_wq(htab, true);
+ htab_free_malloced_timers_or_wq(htab);
else
htab_free_prealloced_timers(htab);
}
- if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) {
- if (!htab_is_prealloc(htab))
- htab_free_malloced_timers_or_wq(htab, false);
- else
- htab_free_prealloced_wq(htab);
- }
}
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
--
2.44.0
