From: Trond Myklebust <Trond.Myklebust@netapp.com>
Date: Tue, 28 Oct 2008 19:21:42 +0000 (-0400)
Subject: SUNRPC: Fix potential race in put_rpccred()
X-Git-Tag: firefly_0821_release~17023^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5f707eb429e2c98dfd564ffbbd9f536bf493d869;p=firefly-linux-kernel-4.4.55.git

SUNRPC: Fix potential race in put_rpccred()

We have to be careful when we try to unhash the credential in
put_rpccred(), because we're not holding the credcache lock, so the call to
rpcauth_unhash_cred() may fail if someone else has looked the cred up, and
obtained a reference to it.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index a045a1253d49..cb216b2df666 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -455,7 +455,7 @@ need_lock:
 	}
 	if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 		rpcauth_unhash_cred(cred);
-	else if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
+	if (test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) {
 		cred->cr_expire = jiffies;
 		list_add_tail(&cred->cr_lru, &cred_unused);
 		number_cred_unused++;