From: Stefan Hajnoczi <[email protected]> Check incoming_posn to avoid out-of-bounds array accesses if the ivshmem server on the host sends invalid values.
Cc: Cam Macdonell <[email protected]> Reported-by: Sebastian Krahmer <[email protected]> Signed-off-by: Stefan Hajnoczi <[email protected]> [AF: Tighten upper bound check for posn in close_guest_eventfds()] Cc: [email protected] Signed-off-by: Andreas Färber <[email protected]> Reviewed-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> (cherry picked from commit 363ba1c72fed4425e7917afc36722584aaeaad8a) Signed-off-by: Michael Roth <[email protected]> --- hw/misc/ivshmem.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 2a05961..02e3dd9 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -385,6 +385,9 @@ static void close_guest_eventfds(IVShmemState *s, int posn) if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { return; } + if (posn < 0 || posn >= s->nb_peers) { + return; + } guest_curr_max = s->peers[posn].nb_eventfds; @@ -451,6 +454,11 @@ static void ivshmem_read(void *opaque, const uint8_t *buf, int size) } } + if (incoming_posn < -1) { + IVSHMEM_DPRINTF("invalid incoming_posn %ld\n", incoming_posn); + return; + } + /* pick off s->server_chr->msgfd and store it, posn should accompany msg */ tmp_fd = qemu_chr_fe_get_msgfd(s->server_chr); IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd); -- 1.9.1
