From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43977) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gX31T-0003he-LG for qemu-devel@nongnu.org; Wed, 12 Dec 2018 06:49:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gX31P-0004DL-Jd for qemu-devel@nongnu.org; Wed, 12 Dec 2018 06:49:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38186) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gX31P-0004Cn-Bu for qemu-devel@nongnu.org; Wed, 12 Dec 2018 06:49:47 -0500 From: P J P Date: Wed, 12 Dec 2018 17:17:25 +0530 Message-Id: <20181212114726.24060-6-ppandit@redhat.com> In-Reply-To: <20181212114726.24060-1-ppandit@redhat.com> References: <20181212114726.24060-1-ppandit@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v1 5/6] pvrdma: check return value from pvrdma_idx_ring_has_ routines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yuval Shaia Cc: Qemu Developers , Marcel Apfelbaum , Saar Amar , Li Qiang , Prasad J Pandit From: Prasad J Pandit pvrdma_idx_ring_has_[data/space] routines also return invalid index PVRDMA_INVALID_IDX[=3D-1], if ring has no data/space. Check return value from these routines to avoid plausible infinite loops. Reported-by: Li Qiang Signed-off-by: Prasad J Pandit --- hw/rdma/vmw/pvrdma_dev_ring.c | 37 +++++++++++++++++------------------ 1 file changed, 18 insertions(+), 19 deletions(-) Update v1: receive error code in idx variable, remove comments -> https://lists.gnu.org/archive/html/qemu-devel/2018-12/msg02342.html diff --git a/hw/rdma/vmw/pvrdma_dev_ring.c b/hw/rdma/vmw/pvrdma_dev_ring.= c index 01247fc041..2dccac8442 100644 --- a/hw/rdma/vmw/pvrdma_dev_ring.c +++ b/hw/rdma/vmw/pvrdma_dev_ring.c @@ -73,23 +73,22 @@ out: =20 void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) { - unsigned int idx =3D 0, offset; + int idx; + unsigned int offset, head; =20 - /* - pr_dbg("%s: t=3D%d, h=3D%d\n", ring->name, ring->ring_state->prod_ta= il, - ring->ring_state->cons_head); - */ - - if (!pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &id= x)) { + idx =3D pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, = &head); + if (idx <=3D 0) { pr_dbg("No more data in ring\n"); return NULL; } =20 + idx =3D pvrdma_idx(&ring->ring_state->cons_head, ring->max_elems); + if (idx < 0 || head !=3D idx) { + pr_dbg("invalid idx\n"); + return NULL; + } + offset =3D idx * ring->elem_sz; - /* - pr_dbg("idx=3D%d\n", idx); - pr_dbg("offset=3D%d\n", offset); - */ return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAG= E_SIZE); } =20 @@ -105,20 +104,20 @@ void pvrdma_ring_read_inc(PvrdmaRing *ring) =20 void *pvrdma_ring_next_elem_write(PvrdmaRing *ring) { - unsigned int idx, offset, tail; + int idx; + unsigned int offset, tail; =20 - /* - pr_dbg("%s: t=3D%d, h=3D%d\n", ring->name, ring->ring_state->prod_ta= il, - ring->ring_state->cons_head); - */ - - if (!pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &t= ail)) { + idx =3D pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems,= &tail); + if (idx <=3D 0) { pr_dbg("CQ is full\n"); return NULL; } =20 idx =3D pvrdma_idx(&ring->ring_state->prod_tail, ring->max_elems); - /* TODO: tail =3D=3D idx */ + if (idx < 0 || tail !=3D idx) { + pr_dbg("invalid idx\n"); + return NULL; + } =20 offset =3D idx * ring->elem_sz; return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAG= E_SIZE); --=20 2.19.2