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authorHoratiu Vultur <horatiu.vultur@microchip.com>2020-05-25 12:55:41 +0300
committerDavid S. Miller <davem@davemloft.net>2020-05-26 04:09:26 +0300
commit617504c67e01d30310558442777a4112ea6d587d (patch)
treef1b8a0e03ddac483345cec7e9588abbfe26c79e4 /net/bridge/br_mrp_netlink.c
parent07153961f82878dee73717f64761d67dff9546c1 (diff)
downloadlinux-617504c67e01d30310558442777a4112ea6d587d.tar.xz
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@syzkaller.appspotmail.com Fixes: 6536993371fa ("bridge: mrp: Integrate MRP into the bridge") Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_mrp_netlink.c')
-rw-r--r--net/bridge/br_mrp_netlink.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c
index 397e7f710772..4a08a99519b0 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;