| Message ID | 20180818171737.29772-1-blp@ovn.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [ovs-dev] netdev-linux: Avoid division by 0 if kernel reports bad scheduler data. | expand |
Looks good to me, thanks. Reviewed-by: Yifeng Sun <pkusunyifeng@gmail.com> On Sat, Aug 18, 2018 at 10:17 AM, Ben Pfaff <blp@ovn.org> wrote: > If the kernel reported a value of 0 for the second value in > /proc/net/psched, it would cause a division-by-zero fault in > read_psched(). I don't know of a kernel that would actually do that, but > it's still better to be safe. > > Found by clang static analyzer > > Reported-by: Bhargava Shastry <bshastry@sect.tu-berlin.de> > Signed-off-by: Ben Pfaff <blp@ovn.org> > --- > lib/netdev-linux.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c > index 0c42268d9d6c..e16ea58a085e 100644 > --- a/lib/netdev-linux.c > +++ b/lib/netdev-linux.c > @@ -5166,7 +5166,7 @@ read_psched(void) > VLOG_DBG("%s: psched parameters are: %u %u %u %u", fn, a, b, c, d); > fclose(stream); > > - if (!a || !c) { > + if (!a || !b || !c) { > VLOG_WARN("%s: invalid scheduler parameters", fn); > goto exit; > } > -- > 2.16.1 > > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev >
Thanks, applied to master and backported. On Mon, Aug 20, 2018 at 09:15:54AM -0700, Yifeng Sun wrote: > Looks good to me, thanks. > > Reviewed-by: Yifeng Sun <pkusunyifeng@gmail.com> > > On Sat, Aug 18, 2018 at 10:17 AM, Ben Pfaff <blp@ovn.org> wrote: > > > If the kernel reported a value of 0 for the second value in > > /proc/net/psched, it would cause a division-by-zero fault in > > read_psched(). I don't know of a kernel that would actually do that, but > > it's still better to be safe. > > > > Found by clang static analyzer > > > > Reported-by: Bhargava Shastry <bshastry@sect.tu-berlin.de> > > Signed-off-by: Ben Pfaff <blp@ovn.org> > > --- > > lib/netdev-linux.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c > > index 0c42268d9d6c..e16ea58a085e 100644 > > --- a/lib/netdev-linux.c > > +++ b/lib/netdev-linux.c > > @@ -5166,7 +5166,7 @@ read_psched(void) > > VLOG_DBG("%s: psched parameters are: %u %u %u %u", fn, a, b, c, d); > > fclose(stream); > > > > - if (!a || !c) { > > + if (!a || !b || !c) { > > VLOG_WARN("%s: invalid scheduler parameters", fn); > > goto exit; > > } > > -- > > 2.16.1 > > > > _______________________________________________ > > dev mailing list > > dev@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > >
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c index 0c42268d9d6c..e16ea58a085e 100644 --- a/lib/netdev-linux.c +++ b/lib/netdev-linux.c @@ -5166,7 +5166,7 @@ read_psched(void) VLOG_DBG("%s: psched parameters are: %u %u %u %u", fn, a, b, c, d); fclose(stream); - if (!a || !c) { + if (!a || !b || !c) { VLOG_WARN("%s: invalid scheduler parameters", fn); goto exit; }
If the kernel reported a value of 0 for the second value in /proc/net/psched, it would cause a division-by-zero fault in read_psched(). I don't know of a kernel that would actually do that, but it's still better to be safe. Found by clang static analyzer Reported-by: Bhargava Shastry <bshastry@sect.tu-berlin.de> Signed-off-by: Ben Pfaff <blp@ovn.org> --- lib/netdev-linux.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)