Thanks. A similar diff was discussed privately with a few
developers during the last few days and is about to be
committed soon.
Martin Natano wrote:
> Another integer overflow: A recv() call with a size of 2^32 bytes causes
> soreceive() to spin in an endless loop, resulting in a system freeze.
> The diff below prevents this behaviour by establishing an upper bound
> for uio_resid before assigning the value to an integer variable with
> smaller width. Also the 'offset' and 'resid' variables are converted to
> use the correct integer types.
>
> cheers,
> natano
>
> Index: kern/uipc_socket.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/uipc_socket.c,v
> retrieving revision 1.144
> diff -u -p -u -r1.144 uipc_socket.c
> --- kern/uipc_socket.c 5 Dec 2015 10:11:53 -0000 1.144
> +++ kern/uipc_socket.c 31 Dec 2015 21:26:01 -0000
> @@ -613,13 +613,14 @@ soreceive(struct socket *so, struct mbuf
> {
> struct mbuf *m, **mp;
> struct mbuf *cm;
> - int flags, len, error, s, offset;
> + int flags, len, error, s;
> + u_long offset;
> struct protosw *pr = so->so_proto;
> struct mbuf *nextrecord;
> int moff, type = 0;
> size_t orig_resid = uio->uio_resid;
> int uio_error = 0;
> - int resid;
> + size_t resid;
>
> mp = mp0;
> if (paddr)
> @@ -639,8 +640,8 @@ soreceive(struct socket *so, struct mbuf
> if (error)
> goto bad;
> do {
> - error = uiomovei(mtod(m, caddr_t),
> - (int) min(uio->uio_resid, m->m_len), uio);
> + error = uiomove(mtod(m, caddr_t),
> + ulmin(uio->uio_resid, m->m_len), uio);
> m = m_free(m);
> } while (uio->uio_resid && error == 0 && m);
> bad:
> @@ -833,11 +834,9 @@ dontblock:
> panic("receive 3");
> #endif
> so->so_state &= ~SS_RCVATMARK;
> - len = uio->uio_resid;
> + len = ulmin(uio->uio_resid, m->m_len - moff);
> if (so->so_oobmark && len > so->so_oobmark - offset)
> len = so->so_oobmark - offset;
> - if (len > m->m_len - moff)
> - len = m->m_len - moff;
> /*
> * If mp is set, just pass back the mbufs.
> * Otherwise copy them out via the uio, then free.
>
