Nikolay Aleksandrov
2020-May-25 08:34 UTC
[Bridge] [PATCH] bridge: mrp: Fix out-of-bounds read in br_mrp_parse
On 25/05/2020 12:55, Horatiu Vultur wrote:> The issue was reported by syzbot. When the function br_mrp_parse was > called with a valid net_bridge_port, the net_bridge was an invalid > pointer. Therefore the check br->stp_enabled could pass/fail > depending where it was pointing in memory. > The fix consists of setting the net_bridge pointer if the port is a > valid pointer. > > Reported-by: syzbot+9c6f0f1f8e32223df9a4 at syzkaller.appspotmail.com > Fixes: 6536993371fa ("bridge: mrp: Integrate MRP into the bridge") > Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com> > --- > net/bridge/br_mrp_netlink.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c > index 397e7f710772a..4a08a99519b04 100644 > --- a/net/bridge/br_mrp_netlink.c > +++ b/net/bridge/br_mrp_netlink.c > @@ -27,6 +27,12 @@ int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p, > struct nlattr *tb[IFLA_BRIDGE_MRP_MAX + 1]; > int err; > > + /* When this function is called for a port then the br pointer is > + * invalid, therefor set the br to point correctly > + */ > + if (p) > + br = p->br; > + > if (br->stp_enabled != BR_NO_STP) { > NL_SET_ERR_MSG_MOD(extack, "MRP can't be enabled if STP is already enabled"); > return -EINVAL; >You should tag the fix for net-next when it's intended for it. Acked-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Horatiu Vultur
2020-May-25 09:55 UTC
[Bridge] [PATCH] bridge: mrp: Fix out-of-bounds read in br_mrp_parse
The issue was reported by syzbot. When the function br_mrp_parse was
called with a valid net_bridge_port, the net_bridge was an invalid
pointer. Therefore the check br->stp_enabled could pass/fail
depending where it was pointing in memory.
The fix consists of setting the net_bridge pointer if the port is a
valid pointer.
Reported-by: syzbot+9c6f0f1f8e32223df9a4 at syzkaller.appspotmail.com
Fixes: 6536993371fa ("bridge: mrp: Integrate MRP into the bridge")
Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>
---
net/bridge/br_mrp_netlink.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c
index 397e7f710772a..4a08a99519b04 100644
--- a/net/bridge/br_mrp_netlink.c
+++ b/net/bridge/br_mrp_netlink.c
@@ -27,6 +27,12 @@ int br_mrp_parse(struct net_bridge *br, struct
net_bridge_port *p,
struct nlattr *tb[IFLA_BRIDGE_MRP_MAX + 1];
int err;
+ /* When this function is called for a port then the br pointer is
+ * invalid, therefor set the br to point correctly
+ */
+ if (p)
+ br = p->br;
+
if (br->stp_enabled != BR_NO_STP) {
NL_SET_ERR_MSG_MOD(extack, "MRP can't be enabled if STP is already
enabled");
return -EINVAL;
--
2.26.2
David Miller
2020-May-26 01:10 UTC
[Bridge] [PATCH] bridge: mrp: Fix out-of-bounds read in br_mrp_parse
From: Horatiu Vultur <horatiu.vultur at microchip.com> Date: Mon, 25 May 2020 09:55:41 +0000> The issue was reported by syzbot. When the function br_mrp_parse was > called with a valid net_bridge_port, the net_bridge was an invalid > pointer. Therefore the check br->stp_enabled could pass/fail > depending where it was pointing in memory. > The fix consists of setting the net_bridge pointer if the port is a > valid pointer. > > Reported-by: syzbot+9c6f0f1f8e32223df9a4 at syzkaller.appspotmail.com > Fixes: 6536993371fa ("bridge: mrp: Integrate MRP into the bridge") > Signed-off-by: Horatiu Vultur <horatiu.vultur at microchip.com>Applied to net-next, thanks.