diff options
| author |   Jakub Sitnicki <jakub@cloudflare.com> | 2020-02-06 12:16:51 +0100 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2020-02-07 22:36:26 +0100 |
| commit | 0b2dc83906cf1e694e48003eae5df8fa63f76fd9 (patch) | |
| tree | 2cb216e87bfd171ea95e8af962f20ed0fa2a3e96 | |
| parent | bpf, sockmap: Don't sleep while holding RCU lock on tear-down (diff) | |
| download | linux-dev-0b2dc83906cf1e694e48003eae5df8fa63f76fd9.tar.xz linux-dev-0b2dc83906cf1e694e48003eae5df8fa63f76fd9.zip | |
bpf, sockhash: Synchronize_rcu before free'ing map
We need to have a synchronize_rcu before free'ing the sockhash because any
outstanding psock references will have a pointer to the map and when they
use it, this could trigger a use after free.
This is a sister fix for sockhash, following commit 2bb90e5cc90e ("bpf:
sockmap, synchronize_rcu before free'ing map") which addressed sockmap,
which comes from a manual audit.
Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200206111652.694507-3-jakub@cloudflare.com
| -rw-r--r-- | net/core/sock_map.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 992504478e68..085cef5857bb 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -250,6 +250,7 @@ static void sock_map_free(struct bpf_map *map) } raw_spin_unlock_bh(&stab->lock); + /* wait for psock readers accessing its map link */ synchronize_rcu(); bpf_map_area_free(stab->sks); @@ -877,6 +878,9 @@ static void sock_hash_free(struct bpf_map *map) raw_spin_unlock_bh(&bucket->lock); } + /* wait for psock readers accessing its map link */ + synchronize_rcu(); + bpf_map_area_free(htab->buckets); kfree(htab); } |