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| author | Greg Kurz <groug@kaod.org> | 2017-06-29 15:11:51 +0200 |
|---|---|---|
| committer | Greg Kurz <groug@kaod.org> | 2017-06-29 15:11:51 +0200 |
| commit | 06a37db7b12e4d42a6699c2fef820158f470ec4f (patch) | |
| tree | f50eb6c26e1bc2804220dc34a95df560f0a06e09 | |
| parent | e08d1e11ed40b93e62ae8973159e6c1a306cd70e (diff) | |
| download | focaccia-qemu-06a37db7b12e4d42a6699c2fef820158f470ec4f.tar.gz focaccia-qemu-06a37db7b12e4d42a6699c2fef820158f470ec4f.zip | |
9pfs: handle transport errors in pdu_complete()
Contrary to what is written in the comment, a buggy guest can misconfigure the transport buffers and pdu_marshal() may return an error. If this ever happens, it is up to the transport layer to handle the situation (9P is transport agnostic). This fixes Coverity issue CID1348518. Signed-off-by: Greg Kurz <groug@kaod.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
| -rw-r--r-- | hw/9pfs/9p.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 8e5cac71eb..6c92bad5b3 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -624,15 +624,11 @@ void pdu_free(V9fsPDU *pdu) QLIST_INSERT_HEAD(&s->free_list, pdu, next); } -/* - * We don't do error checking for pdu_marshal/unmarshal here - * because we always expect to have enough space to encode - * error details - */ static void coroutine_fn pdu_complete(V9fsPDU *pdu, ssize_t len) { int8_t id = pdu->id + 1; /* Response */ V9fsState *s = pdu->s; + int ret; if (len < 0) { int err = -len; @@ -644,11 +640,19 @@ static void coroutine_fn pdu_complete(V9fsPDU *pdu, ssize_t len) str.data = strerror(err); str.size = strlen(str.data); - len += pdu_marshal(pdu, len, "s", &str); + ret = pdu_marshal(pdu, len, "s", &str); + if (ret < 0) { + goto out_notify; + } + len += ret; id = P9_RERROR; } - len += pdu_marshal(pdu, len, "d", err); + ret = pdu_marshal(pdu, len, "d", err); + if (ret < 0) { + goto out_notify; + } + len += ret; if (s->proto_version == V9FS_PROTO_2000L) { id = P9_RLERROR; @@ -657,12 +661,15 @@ static void coroutine_fn pdu_complete(V9fsPDU *pdu, ssize_t len) } /* fill out the header */ - pdu_marshal(pdu, 0, "dbw", (int32_t)len, id, pdu->tag); + if (pdu_marshal(pdu, 0, "dbw", (int32_t)len, id, pdu->tag) < 0) { + goto out_notify; + } /* keep these in sync */ pdu->size = len; pdu->id = id; +out_notify: pdu->s->transport->push_and_notify(pdu); /* Now wakeup anybody waiting in flush for this request */ |