6.1-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ 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 --- drivers/block/nbd.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 120b75ee703d1..2a959c08bd3cb 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1107,6 +1107,14 @@ 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;