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[Qemu-devel] [PATCH v3 2/4] ivshmem: validate incoming_posn value from s
From: |
Andreas Färber |
Subject: |
[Qemu-devel] [PATCH v3 2/4] ivshmem: validate incoming_posn value from server |
Date: |
Mon, 15 Sep 2014 18:40:06 +0200 |
From: Stefan Hajnoczi <address@hidden>
Check incoming_posn to avoid out-of-bounds array accesses if the ivshmem
server on the host sends invalid values.
Cc: Cam Macdonell <address@hidden>
Reported-by: Sebastian Krahmer <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
[AF: Tighten upper bound check for posn in close_guest_eventfds()]
Cc: address@hidden
Signed-off-by: Andreas Färber <address@hidden>
---
hw/misc/ivshmem.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index caeee1e..24f74f6 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -389,6 +389,9 @@ 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;
@@ -455,6 +458,11 @@ 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);
--
1.8.4.5