From: Eric Dumazet <edumazet@google.com> stable inclusion from stable-v6.6.112 commit 4f9e6ff6319dbcebea64b50af0304cf0ad7e97e7 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ID3WIC CVE: CVE-2025-40080 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ------------------ [ Upstream commit 9f7c02e031570e8291a63162c6c046dc15ff85b0 ] Recently, syzbot started to abuse NBD with all kinds of sockets. Commit cf1b2326b734 ("nbd: verify socket is supported during setup") made sure the socket supported a shutdown() method. Explicitely accept TCP and UNIX stream sockets. Fixes: cf1b2326b734 ("nbd: verify socket is supported during setup") Reported-by: syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/CANn89iJ+76eE3A_8S_zTpSyW5hvPRn6V57458hCZGY5h... Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Mike Christie <mchristi@redhat.com> Cc: Richard W.M. Jones <rjones@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Yu Kuai <yukuai1@huaweicloud.com> Cc: linux-block@vger.kernel.org Cc: nbd@other.debian.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Qixing <zhengqixing@huawei.com> --- drivers/block/nbd.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 7eeb4b6de6de..26e1cf7f666c 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1128,6 +1128,14 @@ static struct socket *nbd_get_socket(struct nbd_device *nbd, unsigned long fd, if (!sock) return NULL; + if (!sk_is_tcp(sock->sk) && + !sk_is_stream_unix(sock->sk)) { + dev_err(disk_to_dev(nbd->disk), "Unsupported socket: should be TCP or UNIX.\n"); + *err = -EINVAL; + sockfd_put(sock); + return NULL; + } + if (sock->ops->shutdown == sock_no_shutdown) { dev_err(disk_to_dev(nbd->disk), "Unsupported socket: shutdown callout must be supported.\n"); *err = -EINVAL; -- 2.39.2