From c9b773eafe1d576e576149bb2c8173d2c9a80683 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] tcp: Fix use-after-free of nreq in reqsk_timer_handler(). BugLink: https://bugs.launchpad.net/bugs/2101915 [ Upstream commit c31e72d021db2714df03df6c42855a1db592716c ] 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(). Fixes: e8c526f2bdf1 ("tcp/dccp: Don't use timer_pending() in reqsk_queue_unlink().") Reported-by: Liu Jian Closes: https://lore.kernel.org/netdev/1284490f-9525-42ee-b7b8-ccadf6606f6d@huawei.com/ Signed-off-by: Kuniyuki Iwashima Reviewed-by: Vadim Fedorenko Reviewed-by: Liu Jian Reviewed-by: Eric Dumazet Reviewed-by: Martin KaFai Lau Link: https://patch.msgid.link/20241123174236.62438-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- net/ipv4/inet_connection_sock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 922470ca1128..1944c53c08c8 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -1128,7 +1128,7 @@ no_ownership: drop: __inet_csk_reqsk_queue_drop(sk_listener, oreq, true); - reqsk_put(req); + reqsk_put(oreq); } static bool reqsk_queue_hash_req(struct request_sock *req,