When MSG_COPY is set, a duplicate message must be allocated for the copy before locking the queue. However, the copy could not be larger than was sent which is limited to msg_ctlmax.
Signed-off-by: Peter Hurley <[email protected]> --- ipc/msg.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/ipc/msg.c b/ipc/msg.c index 950572f..31cd1bf 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -820,15 +820,17 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, struct msg_msg *copy = NULL; unsigned long copy_number = 0; + ns = current->nsproxy->ipc_ns; + if (msqid < 0 || (long) bufsz < 0) return -EINVAL; if (msgflg & MSG_COPY) { - copy = prepare_copy(buf, bufsz, msgflg, &msgtyp, ©_number); + copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax), + msgflg, &msgtyp, ©_number); if (IS_ERR(copy)) return PTR_ERR(copy); } mode = convert_mode(&msgtyp, msgflg); - ns = current->nsproxy->ipc_ns; msq = msg_lock_check(ns, msqid); if (IS_ERR(msq)) { -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
