From nobody Sat Sep 26 21:15:55 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 56C0735C1A9; Sun, 30 Aug 2026 07:09:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788073799; cv=none; b=NaBUaIoSIzzNlOD6qyY6DL0tNqucYKFVkQLy8L9Qu57NYNwY7KrvuZV5crBIhYeXbhX88ZxAnR8VuRNWJNlzx1xyATJfVwXYevl4Q65HyMYlANAaEtQn7AcimUSDgifNtiV2ljfA5nddAu5D8Ptrnk+AjqFD5gTIK5SUYieQTUI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788073799; c=relaxed/simple; bh=WUy6WoO/WqUl1q9oVvwQFB+Di9tkCZw+1WB5W+xqYpc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=kHStPVQy+7XHXauuQM7tS/DIdGIEm9DmfFBYfLPzP9WbfcEpTkpcL0GeKzAMCJVNgdbowUyCNYo1BLHRv04NMdcRo90E+2QgdGTCxszw6fqdjjR+imFLG3b5KwVkCT5HCEHqCZdi6UlrTXinnTWfUtqIUlckiNxj/P/FLp+z4e8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JFUnuKTD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JFUnuKTD" Received: by smtp.kernel.org (Postfix) with ESMTPS id 56737C2BCF4; Sun, 30 Aug 2026 07:09:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1788073798; bh=WUy6WoO/WqUl1q9oVvwQFB+Di9tkCZw+1WB5W+xqYpc=; h=From:Date:Subject:To:Cc:Reply-To:From; b=JFUnuKTDT8omAZKCvVKCOpwb7oZgRhlEgwN7hh3qbsL/T9f/DO0prBrW5TVmGpEiJ i6g84lJ8ZMCzCCnQEuvwRvkmDO64k+D5TAy3DoSYT05duA4nYtH8J8ify7e8NeHDUZ gjn1GfHi9athTb2Phs0q54hGSqK4t5LEBE1UbQWsxObLW5XbX3e9GRMHFDOVk+nKpE lRR//Ma35v7WHxbfsKEmDYNBrxrp9oT+xWlMOrN4QIYRP4O8ymWF0mLyFT0zQNh1VQ t+Um/J0NxjSyKY1B1YRjEPDQf5M958eQz0+bRXAH4+M3A1x+PelTLvx2mBruKJJS1R a+/FvS8tX7wrA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43CDEC61DE2; Sun, 30 Aug 2026 07:09:58 +0000 (UTC) From: Quanye Yang via B4 Relay Date: Sun, 30 Aug 2026 15:09:55 +0800 Subject: [PATCH] RDMA/rtrs-clt: Fix CQ pool leak when connect is interrupted Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260830-rdma-rtrs-clt-cq-pool-leak-v1-1-b169434fd3df@proton.me> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/yXMwQ6CMAwA0F8hPdtkA+KIv2I8jFG0Ohm005AQ/ t2px3d5GygJk8Kp2kDozcppKrCHCsLNT1dCHoqhNvXRdI1BGZ4eJYtiiBnDgnNKESP5B7putL1 xjprWQglmoZHXX36+/K2v/k4hf0fY9w/JgTQkfgAAAA== X-Change-ID: 20260830-rdma-rtrs-clt-cq-pool-leak-78f1b077e341 To: "Md. Haris Iqbal" , Jack Wang , Jason Gunthorpe , Leon Romanovsky Cc: Jack Wang , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+d396918a29afb8543e1c@syzkaller.appspotmail.com, Quanye Yang X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1788073795; l=3778; i=quanyeyang@proton.me; s=20260801; h=from:subject:message-id; bh=cn9IkRUu0B89uWfK7vLWOhB21IgObrIMhVPL+RLvT4M=; b=aDuIS6UusZbS31KSqt2aMZnI1gtCGGold4AKeQ8ALgGzI9GcUH8Rxd2ul3d4COI5PPUaBxmHb 6dVUDASJ/bWCiY+RaiE8sp1ALqEDqC8ASBTQjiJx0xgPfa8rdyhgCgx X-Developer-Key: i=quanyeyang@proton.me; a=ed25519; pk=9L9FrcvzMgxPaBRU6XV0EnqTgjDqVO596rQKSZ9qZoY= X-Endpoint-Received: by B4 Relay for quanyeyang@proton.me/20260801 with auth_id=963 X-Original-From: Quanye Yang Reply-To: quanyeyang@proton.me From: Quanye Yang The client borrows shared CQ credits in the ADDR_RESOLVED handler via ib_cq_pool_get(), before the peer is connected. create_cm() can return -ERESTARTSYS from wait_event_interruptible_timeout() without destroying the CM ID. The init_conns() and stop-and-destroy paths then call destroy_con_cq_qp() while cq is still NULL (no PUT) and only afterwards rdma_destroy_id(). CMA serializes the handler against rdma_destroy_id() with handler_mutex, but that does not order the GET against destroy_con_cq_qp(). If ADDR_RESOLVED has already passed the DESTROYING check, it can take con_mutex, GET credits, and then lose the con to kfree. Device unregister later hits WARN_ON(cq->cqe_used) in ib_cq_pool_cleanup(). Set a per-connection flag under con_mutex before CQ/QP teardown so a racing ADDR_RESOLVED cannot borrow credits after teardown has begun. Reported-by: syzbot+d396918a29afb8543e1c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3Dd396918a29afb8543e1c Fixes: 3b89e92c2a95 ("RDMA/rtrs: Use new shared CQ mechanism") Signed-off-by: Quanye Yang Reviewed-by: Jack Wang --- Fix a syzbot WARNING in ib_cq_pool_cleanup(): an ADDR_RESOLVED handler can ib_cq_pool_get() after connection teardown has already skipped the matching PUT. Reproduced on rxe with rnbd-client only (no rtrs server): write map_device with path=3Dip:127.0.0.1, interrupt create_cm() with a signal, then rdma link delete. Device unregister no longer reports leftover cqe_used after this change. --- drivers/infiniband/ulp/rtrs/rtrs-clt.c | 8 ++++++++ drivers/infiniband/ulp/rtrs/rtrs-clt.h | 2 ++ 2 files changed, 10 insertions(+) diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ul= p/rtrs/rtrs-clt.c index 7b2c51ae614f..eac38b57b00d 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c @@ -1732,6 +1732,8 @@ static void destroy_con_cq_qp(struct rtrs_clt_con *co= n) /* * Be careful here: destroy_con_cq_qp() can be called even * create_con_cq_qp() failed, see comments there. + * Caller must set con->destroyed under this lock first so a + * racing ADDR_RESOLVED cannot ib_cq_pool_get() after we PUT/SKIP. */ lockdep_assert_held(&con->con_mutex); rtrs_cq_qp_destroy(&con->c); @@ -1766,6 +1768,10 @@ static int rtrs_rdma_addr_resolved(struct rtrs_clt_c= on *con) int err; =20 mutex_lock(&con->con_mutex); + if (con->destroyed) { + mutex_unlock(&con->con_mutex); + return -ECONNABORTED; + } err =3D create_con_cq_qp(con); mutex_unlock(&con->con_mutex); if (err) { @@ -2221,6 +2227,7 @@ static void rtrs_clt_stop_and_destroy_conns(struct rt= rs_clt_path *clt_path) break; con =3D to_clt_con(clt_path->s.con[cid]); mutex_lock(&con->con_mutex); + con->destroyed =3D true; destroy_con_cq_qp(con); mutex_unlock(&con->con_mutex); destroy_cm(con); @@ -2387,6 +2394,7 @@ static int init_conns(struct rtrs_clt_path *clt_path) if (con->c.cm_id) { stop_cm(con); mutex_lock(&con->con_mutex); + con->destroyed =3D true; destroy_con_cq_qp(con); mutex_unlock(&con->con_mutex); destroy_cm(con); diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.h b/drivers/infiniband/ul= p/rtrs/rtrs-clt.h index 1305601a6251..ad64f4517c4b 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.h +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.h @@ -75,6 +75,8 @@ struct rtrs_clt_con { unsigned int cpu; struct mutex con_mutex; int cm_err; + /* Set under con_mutex before CQ/QP teardown. */ + bool destroyed; }; =20 /** --- base-commit: 08dbfad3f5040f5bdb6c529da20d6d4e81fefd72 change-id: 20260830-rdma-rtrs-clt-cq-pool-leak-78f1b077e341 Best regards, -- =20 Quanye Yang