In the Linux kernel, the following vulnerability has been resolved: tcp: Fix use-after-free of nreq in reqsk_timer_handler(). The cited commit replaced inet_csk_reqsk_queue_drop_and_put() with __inet_csk_reqsk_queue_drop() and reqsk_put() in reqsk_timer_handler(). Then, oreq should be passed to reqsk_put() instead of req; otherwise use-after-free of nreq could happen when reqsk is migrated but the retry attempt failed (e.g. due to timeout). Let's pass oreq to reqsk_put().
https://git.kernel.org/stable/c/d0eb14cb8c08b00c36a3d5dc57a6f428b301f721
https://git.kernel.org/stable/c/c31e72d021db2714df03df6c42855a1db592716c
https://git.kernel.org/stable/c/9a3c1ad93e6fba67b3a637cfa95a57a6685e4908
https://git.kernel.org/stable/c/6d845028609a4af0ad66f499ee0bd5789122b067
https://git.kernel.org/stable/c/65ed89cad1f57034c256b016e89e8c0a4ec7c65b
https://git.kernel.org/stable/c/2dcc86fefe09ac853158afd96b60d544af115dc5