5a6f687360
Splicing to SOCK_RAW sockets may set MSG_SPLICE_PAGES, but in such a case, __ip_append_data() will call skb_splice_from_iter() to access the 'from' data, assuming it to point to a msghdr struct with an iter, instead of using the provided getfrag function to access it. In the case of raw_sendmsg(), however, this is not the case and 'from' will point to a raw_frag_vec struct and raw_getfrag() will be the frag-getting function. A similar issue may occur with rawv6_sendmsg(). Fix this by ignoring MSG_SPLICE_PAGES if getfrag != ip_generic_getfrag as ip_generic_getfrag() expects "from" to be a msghdr*, but the other getfrags don't. Note that this will prevent MSG_SPLICE_PAGES from being effective for udplite. This likely affects ping sockets too. udplite looks like it should be okay as it expects "from" to be a msghdr. Signed-off-by: David Howells <dhowells@redhat.com> Reported-by: syzbot+d8486855ef44506fd675@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/000000000000ae4cbf05fdeb8349@google.com/ Fixes: 2dc334f1a63a ("splice, net: Use sendmsg(MSG_SPLICE_PAGES) rather than ->sendpage()") Tested-by: syzbot+d8486855ef44506fd675@syzkaller.appspotmail.com cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/1410156.1686729856@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>