In the Linux kernel, the following vulnerability has been resolved: net: fix memory leak in tcp_conn_request() If inet_csk_reqsk_queue_hash_add() return false, tcp_conn_request() will return without free the dst memory, which allocated in af_ops->route_req. Here is the kmemleak stack: unreferenced object 0xffff8881198631c0 (size 240): comm "softirq", pid 0, jiffies 4299266571 (age 1802.392s) hex dump (first 32 bytes): 00 10 9b 03 81 88 ff ff 80 98 da bc ff ff ff ff ................ 81 55 18 bb ff ff ff ff 00 00 00 00 00 00 00 00 .U.............. backtrace: [<ffffffffb93e8d4c>] kmem_cache_alloc+0x60c/0xa80 [<ffffffffba11b4c5>] dst_alloc+0x55/0x250 [<ffffffffba227bf6>] rt_dst_alloc+0x46/0x1d0 [<ffffffffba23050a>] __mkroute_output+0x29a/0xa50 [<ffffffffba23456b>] ip_route_output_key_hash+0x10b/0x240 [<ffffffffba2346bd>] ip_route_output_flow+0x1d/0x90 [<ffffffffba254855>] inet_csk_route_req+0x2c5/0x500 [<ffffffffba26b331>] tcp_conn_reque…