From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48010) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gWi65-0002SD-Nk for qemu-devel@nongnu.org; Tue, 11 Dec 2018 08:29:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gWi64-0000lT-Df for qemu-devel@nongnu.org; Tue, 11 Dec 2018 08:29:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56118) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gWi63-0000kT-Ok for qemu-devel@nongnu.org; Tue, 11 Dec 2018 08:29:12 -0500 From: P J P Date: Tue, 11 Dec 2018 18:56:42 +0530 Message-Id: <20181211132642.3027-6-ppandit@redhat.com> In-Reply-To: <20181211132642.3027-1-ppandit@redhat.com> References: <20181211132642.3027-1-ppandit@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH 5/5] pvrdma: check return value from pvrdma_idx_ring_has_ routines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Yuval Shaia , 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 | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/hw/rdma/vmw/pvrdma_dev_ring.c b/hw/rdma/vmw/pvrdma_dev_ring.= c index 01247fc041..61b6a0a869 100644 --- a/hw/rdma/vmw/pvrdma_dev_ring.c +++ b/hw/rdma/vmw/pvrdma_dev_ring.c @@ -73,6 +73,7 @@ out: =20 void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) { + int e; unsigned int idx =3D 0, offset; =20 /* @@ -80,7 +81,8 @@ void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) ring->ring_state->cons_head); */ =20 - if (!pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &id= x)) { + e =3D pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &i= dx); + if (e <=3D 0) { pr_dbg("No more data in ring\n"); return NULL; } @@ -105,20 +107,24 @@ 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=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