From ce9c139d93db03e464341385976606b7568b768f Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 18 Jul 2016 16:30:36 +0100 Subject: [PATCH] linux-user: Range check the nfds argument to ppoll syscall Do an initial range check on the ppoll syscall's nfds argument, to avoid possible overflow in the calculation of the lock_user() size argument. The host kernel will later apply the rather lower limit based on RLIMIT_NOFILE as appropriate. Signed-off-by: Peter Maydell Signed-off-by: Riku Voipio --- linux-user/syscall.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index eecccbb25c..7a50a57d4b 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -9661,6 +9661,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, pfd = NULL; target_pfd = NULL; if (nfds) { + if (nfds > (INT_MAX / sizeof(struct target_pollfd))) { + ret = -TARGET_EINVAL; + break; + } + target_pfd = lock_user(VERIFY_WRITE, arg1, sizeof(struct target_pollfd) * nfds, 1); if (!target_pfd) {