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From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
        "David Teigland" <teigland@redhat.com>,
        "Vasily Averin" <vvs@virtuozzo.com>
Date:   Tue, 02 Apr 2019 14:38:27 +0100
Message-ID: <lsq.1554212307.717224544@decadent.org.uk>
Subject: [PATCH 3.16 08/99] dlm: memory leaks on error path in
 dlm_user_request()
In-Reply-To: <lsq.1554212307.17110877@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

3.16.65-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Vasily Averin <vvs@virtuozzo.com>

commit d47b41aceeadc6b58abc9c7c6485bef7cfb75636 upstream.

According to comment in dlm_user_request() ua should be freed
in dlm_free_lkb() after successful attach to lkb.

However ua is attached to lkb not in set_lock_args() but later,
inside request_lock().

Fixes 597d0cae0f99 ("[DLM] dlm: user locks")

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 fs/dlm/lock.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -5795,20 +5795,20 @@ int dlm_user_request(struct dlm_ls *ls,
 			goto out;
 		}
 	}
-
-	/* After ua is attached to lkb it will be freed by dlm_free_lkb().
-	   When DLM_IFL_USER is set, the dlm knows that this is a userspace
-	   lock and that lkb_astparam is the dlm_user_args structure. */
-
 	error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs,
 			      fake_astfn, ua, fake_bastfn, &args);
-	lkb->lkb_flags |= DLM_IFL_USER;
-
 	if (error) {
+		kfree(ua->lksb.sb_lvbptr);
+		ua->lksb.sb_lvbptr = NULL;
+		kfree(ua);
 		__put_lkb(ls, lkb);
 		goto out;
 	}
 
+	/* After ua is attached to lkb it will be freed by dlm_free_lkb().
+	   When DLM_IFL_USER is set, the dlm knows that this is a userspace
+	   lock and that lkb_astparam is the dlm_user_args structure. */
+	lkb->lkb_flags |= DLM_IFL_USER;
 	error = request_lock(ls, lkb, name, namelen, &args);
 
 	switch (error) {