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authorJakub Sitnicki <jakub@cloudflare.com>2020-06-07 22:52:28 +0200
committerAlexei Starovoitov <ast@kernel.org>2020-06-09 10:59:04 -0700
commit33a7c831565c43a7ee2f38c7df4c4a40e1dfdfed (patch)
tree4fc699753e28804774c573e851794ef7c8acc1b5
parent487082fb7bd2a32b66927d2b22e3a81b072b44f0 (diff)
downloadlinux-33a7c831565c43a7ee2f38c7df4c4a40e1dfdfed.tar.gz
bpf, sockhash: Fix memory leak when unlinking sockets in sock_hash_free
When sockhash gets destroyed while sockets are still linked to it, we will walk the bucket lists and delete the links. However, we are not freeing the list elements after processing them, leaking the memory. The leak can be triggered by close()'ing a sockhash map when it still contains sockets, and observed with kmemleak: unreferenced object 0xffff888116e86f00 (size 64): comm "race_sock_unlin", pid 223, jiffies 4294731063 (age 217.404s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 81 de e8 41 00 00 00 00 c0 69 2f 15 81 88 ff ff ...A.....i/..... backtrace: [<00000000dd089ebb>] sock_hash_update_common+0x4ca/0x760 [<00000000b8219bd5>] sock_hash_update_elem+0x1d2/0x200 [<000000005e2c23de>] __do_sys_bpf+0x2046/0x2990 [<00000000d0084618>] do_syscall_64+0xad/0x9a0 [<000000000d96f263>] entry_SYSCALL_64_after_hwframe+0x49/0xb3 Fix it by freeing the list element when we're done with it. Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200607205229.2389672-2-jakub@cloudflare.com
-rw-r--r--net/core/sock_map.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 00a26cf..ea46f07 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -1031,6 +1031,7 @@ static void sock_hash_free(struct bpf_map *map)
sock_map_unref(elem->sk, elem);
rcu_read_unlock();
release_sock(elem->sk);
+ sock_hash_free_elem(htab, elem);
}
}