On 28/03/2026 08:30, Xiang Mei wrote:
br_mrp_start_test() and br_mrp_start_in_test() accept the user-supplied interval value from netlink without validation. When interval is 0, usecs_to_jiffies(0) yields 0, causing the delayed work (br_mrp_test_work_expired / br_mrp_in_test_work_expired) to reschedule itself with zero delay. This creates a tight loop on system_percpu_wq that allocates and transmits MRP test frames at maximum rate, exhausting all system memory and causing a kernel panic via OOM deadlock.The same zero-interval issue applies to br_mrp_start_in_test_parse() for interconnect test frames. Use NLA_POLICY_MIN(NLA_U32, 1) in the nla_policy tables for both IFLA_BRIDGE_MRP_START_TEST_INTERVAL and IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL, so zero is rejected at the netlink attribute parsing layer before the value ever reaches the workqueue scheduling code. This is consistent with how other bridge subsystems (br_fdb, br_mst) enforce range constraints on netlink attributes. Fixes: 20f6a05ef635 ("bridge: mrp: Rework the MRP netlink interface") Fixes: 7ab1748e4ce6 ("bridge: mrp: Extend MRP netlink interface for configuring MRP interconnect") Reported-by: Weiming Shi <[email protected]> Signed-off-by: Xiang Mei <[email protected]> --- net/bridge/br_mrp_netlink.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c index ce6f63c77cc0..86f0e75d6e34 100644 --- a/net/bridge/br_mrp_netlink.c +++ b/net/bridge/br_mrp_netlink.c @@ -196,7 +196,7 @@ static const struct nla_policy br_mrp_start_test_policy[IFLA_BRIDGE_MRP_START_TEST_MAX + 1] = { [IFLA_BRIDGE_MRP_START_TEST_UNSPEC] = { .type = NLA_REJECT }, [IFLA_BRIDGE_MRP_START_TEST_RING_ID] = { .type = NLA_U32 }, - [IFLA_BRIDGE_MRP_START_TEST_INTERVAL] = { .type = NLA_U32 }, + [IFLA_BRIDGE_MRP_START_TEST_INTERVAL] = NLA_POLICY_MIN(NLA_U32, 1), [IFLA_BRIDGE_MRP_START_TEST_MAX_MISS] = { .type = NLA_U32 }, [IFLA_BRIDGE_MRP_START_TEST_PERIOD] = { .type = NLA_U32 }, [IFLA_BRIDGE_MRP_START_TEST_MONITOR] = { .type = NLA_U32 }, @@ -316,7 +316,7 @@ static const struct nla_policy br_mrp_start_in_test_policy[IFLA_BRIDGE_MRP_START_IN_TEST_MAX + 1] = { [IFLA_BRIDGE_MRP_START_IN_TEST_UNSPEC] = { .type = NLA_REJECT }, [IFLA_BRIDGE_MRP_START_IN_TEST_IN_ID] = { .type = NLA_U32 }, - [IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL] = { .type = NLA_U32 }, + [IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL] = NLA_POLICY_MIN(NLA_U32, 1), [IFLA_BRIDGE_MRP_START_IN_TEST_MAX_MISS] = { .type = NLA_U32 }, [IFLA_BRIDGE_MRP_START_IN_TEST_PERIOD] = { .type = NLA_U32 }, };
Alright, let's limit them :-) Acked-by: Nikolay Aleksandrov <[email protected]>
