mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-12-30 20:36:16 -05:00
4fe38acdac
It is necessary to allow MSG_SENDPAGE_* to be passed into ->sendmsg() to allow sendmsg(MSG_SPLICE_PAGES) to replace ->sendpage(). Unblocking them in the network protocol, however, allows these flags to be passed in by userspace too[1]. Fix this by marking MSG_SENDPAGE_NOPOLICY, MSG_SENDPAGE_NOTLAST and MSG_SENDPAGE_DECRYPTED as internal flags, which causes sendmsg() to object if they are passed to sendmsg() by userspace. Network protocol ->sendmsg() implementations can then allow them through. Note that it should be possible to remove MSG_SENDPAGE_NOTLAST once sendpage is removed as a whole slew of pages will be passed in in one go by splice through sendmsg, with MSG_MORE being set if it has more data waiting in the pipe. Signed-off-by: David Howells <dhowells@redhat.com> cc: Chuck Lever <chuck.lever@oracle.com> cc: Boris Pismenny <borisp@nvidia.com> cc: John Fastabend <john.fastabend@gmail.com> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Link: https://lore.kernel.org/r/20230526181338.03a99016@kernel.org/ [1] Signed-off-by: Jakub Kicinski <kuba@kernel.org>