From: Kuniyuki Iwashima Date: Tue, 8 Apr 2025 22:40:54 +0000 (-0700) Subject: nvme-tcp: fix use-after-free of netns by kernel TCP socket. X-Git-Tag: nvme-6.15-2025-04-10~8 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b013b817f32fb8c560b6970e1002e94f1c725923;p=nvme.git nvme-tcp: fix use-after-free of netns by kernel TCP socket. Commit 1be52169c348 ("nvme-tcp: fix selinux denied when calling sock_sendmsg") converted sock_create() in nvme_tcp_alloc_queue() to sock_create_kern(). sock_create_kern() creates a kernel socket, which does not hold a reference to netns. If the code does not manage the netns lifetime properly, use-after-free could happen. Also, TCP kernel socket with sk_net_refcnt 0 has a socket leak problem: it remains FIN_WAIT_1 if it misses FIN after close() because tcp_close() stops all timers. To fix such problems, let's hold netns ref by sk_net_refcnt_upgrade(). We had the same issue in CIFS, SMC, etc, and applied the same solution, see commit ef7134c7fc48 ("smb: client: Fix use-after-free of network namespace.") and commit 9744d2bf1976 ("smc: Fix use-after-free in tcp_write_timer_handler()."). Fixes: 1be52169c348 ("nvme-tcp: fix selinux denied when calling sock_sendmsg") Signed-off-by: Kuniyuki Iwashima Signed-off-by: Christoph Hellwig --- diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 26c459f0198d..72d260201d8c 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1803,6 +1803,8 @@ static int nvme_tcp_alloc_queue(struct nvme_ctrl *nctrl, int qid, ret = PTR_ERR(sock_file); goto err_destroy_mutex; } + + sk_net_refcnt_upgrade(queue->sock->sk); nvme_tcp_reclassify_socket(queue->sock); /* Single syn retry */