tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv

tipc_crypto_rcv() invokes tipc_aead_get(), which returns a reference of
the tipc_aead object to "aead" with increased refcnt.

When tipc_crypto_rcv() returns, the original local reference of "aead"
becomes invalid, so the refcount should be decreased to keep refcount
balanced.

The issue happens in one error path of tipc_crypto_rcv(). When TIPC
message decryption status is EINPROGRESS or EBUSY, the function forgets
to decrease the refcnt increased by tipc_aead_get() and causes a refcnt
leak.

Fix this issue by calling tipc_aead_put() on the error path when TIPC
message decryption status is EINPROGRESS or EBUSY.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/crypto.c b/net/tipc/crypto.c
index c8c47fc7265361229c9e19f7e46eeb840089d93d..8c47ded2edb6143d3a79782e5f8404546a726ac4 100644 (file)
--- a/net/tipc/crypto.c
+++ b/net/tipc/crypto.c
@@ -1712,6 +1712,7 @@ exit:
        case -EBUSY:
                this_cpu_inc(stats->stat[STAT_ASYNC]);
                *skb = NULL;
+               tipc_aead_put(aead);
                return rc;
        default:
                this_cpu_inc(stats->stat[STAT_NOK]);